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Garage => Mechanicals => Topic started by: WGB on 20 April 2007, 10:15 AM

Title: 450 - M117 Timing Chain Replacement
Post by: WGB on 20 April 2007, 10:15 AM
The archilles heel of the M116 and M117 motor is the timing chain and many a good car will die an early death if the timing chain is not changed every 100,000 miles and particularly in conjuction with the plastic sliders and hydraulic tensioner with it's own plastic slider (Liner). It was also recommended that I change the camshaft sprockets as well as this would assist in getting the cam timing nearer correct.

First job was to secure the parts and this is what was purchased along with some new Cam cover gaskets, a new auxillary air valve and a new fuel filter.

(http://gallery.w116.org/dl/9748-4/Necessary+Supplies.JPG)


The air-cleaner, Sparkplugs,fan, Battery and battery holder, and radiator were removed and a bag was placed over the throttle body to stop any stray parts dropping into the engine.

The engine was turned clockwise (looking from the front of the car) on the crankshaft nut to TDC - never go backwards at all and if necessary only 1 or 2 degrees to make something fit

(http://gallery.w116.org/dl/9755-3/Radiator+removed.jpg)

Next all the ancillaries including belts, pulleys, alternator, distributor and power steering were unbolted and removed. The position of the distributor at TDC was marked to make a good starting point for the timing at reassembly.

The power steering pump and reservoir were left connected to the pipework and tied to the side of the engine bay so as to spill as little oil as possible.

(http://gallery.w116.org/dl/9760-3/Ancillaries+need+stripping.jpg)

The camcovers were removed and on my car (with 168,000 recorded miles) the sprockets and sliders were original but the chain had been replaced at some time as it had a joining master link vbisible.

The chain stretch is measured by aligning the RH camshaft timing marks by rotating the motor with the crankchaft pulley nut (Clockwise only) using a socket, short extension and a large ratcheting torque wrench which I own.

(http://gallery.w116.org/dl/9761-3/RH+Cam+-+timing+marks+aligned.jpg)

Here is a view of Right Hand Cam timing marks  - in alignment

(http://gallery.w116.org/dl/9766-3/Left+hand+cam+tower+showing+ATDC.jpg)

At the same time here is the Left hand cam alignment marks showing that the chain has stretched and that the sprockets are worn as the marks do not align.

(http://gallery.w116.org/dl/9767-3/10+degrees+ATDC.jpg)

Again at the same time the crankshaft is reading 10 degrees after TDC - maximum chain stretch is 11 degrees ATDC on a 117 motor.

(http://gallery.w116.org/dl/9772-3/Old+slider+-+new+slider.jpg)

The next step is to change all the sliders, cogs and tensioner with it's slider before the old chain is touched.

The sprockets and sliders can be removed without splitting the chain by removing the tensioner and giving sufficient slack for the sprockets to be removed.

They will need to be removed (One side at a time)  to give enough clearance to remove and replace the sliders.

Here is a view of a new white coloured slider sitting on top of the chain to show the contrast with the old very dark brown slider in it's correct position

(http://gallery.w116.org/dl/9773-3/New+and+old+Sprocket+and+slider.jpg)

Here is a new slider and cog alongside an old slider and cog. There is a spark plug socket with a bolt through it which has been used as an extractor to remove a slider pin.

The pins (2 per slider) are held into the heads by friction only and are internally threaded to allow a bolt to be threaded into them for extraction. The factory method is to use a slide hammer on these attached bolts. The non-factory method is to use a nut on the thread of the correct sized bolt working against packing which is placed between nut and head material or if there is room the bolt is pulled through a spark plug spanner.
The pins are very tight and the surface of the head is not smooth so patience and different types of packing are used to get a straight pull

(http://gallery.w116.org/dl/9780-3/Pulling+Slider+Pins.jpg)

The left hand head has ribs on the front and here I have used an open ended spanner to keep the packing straight and am using the nut as the means of leverage.

To replace the sliders you will have to remove the sprockets whether you change them or not, just to give adequate clearance for removal and replacement of the slider pieces. You should use cable ties to hold the chain in position on the sprockets, then unbolt the sprockets while using a screwdriver through the sprocket hole to steady it and then keep the chain in tension so that it cannot move on the crankshaft sprocket .

The sliders are replaced and the pins driven back in with a bolt screwed into the end and gentle taps with a hammer.

The old tensioner is removed by removing the two bolts that locate it.

To remove the tensioner slider the lower pivot point has to be released. It is housed inside a cap low on the front of the motor. The cap is unscrewed and inside is a hollow pin which can be extracted by slipping a phillips head screwdriver into it and jiggling the tensioner arm and the screwdriver until it appears - may be worth tying a piece of wire to  the top of the slipper so that it doesn't drop too far but from memory it can't drop right down.

The plastic lining of the tensioner slider is replaced by unclipping the old liner and clipping on a new one - locating lugs are moulded into the ends of the plastic liner.

While the tension is off the chain I replaced the Camshaft sprockets with new ones taking care to keep the teeth and keyway position in alignment.

The new tensioner was filled with oil and screwed in to keep the old chain in tension.

At this point the old chain was clamped to the RH sprocket with cable ties and the master link divided . I used newspaper to stop anything dropping into the motor. If there is an original chain with no master link a link must have it's peened ends ground off with a small grinder like a Dremel to enable it to be joined with the new chain.

(http://gallery.w116.org/dl/9777-4/New+chain+joined+with+old+masterlink.jpg)

Here is the old cable joined to the new cable. The method calls for large re-usable cable ties but I didn't have any so I used a large packet of non-reusable ones and cut them when they needed to be removed. I found I needed two per time to stop the chain from slipping on the sprockets - next time I would use Vise-Grips with tape or plastic pipe on the jaws.

(http://gallery.w116.org/dl/9786-3/Feeding+in+new+chain+from+Box.jpg)

Here the new chain is being fed from the box sitting at the side of the engine bay while the old chain just continues to fall to the ground down the side of the motor with the crankshaft bolt being slowly turned clockwise.

(http://gallery.w116.org/dl/9787-3/New+Chain+Link.jpg)

Here is the new master link with the new more robust tiny C-clamps - it's a real art to get these on without dropping anything - I again filled the space below with newspaper in case I dropped anything and had magnets on standby.

(http://gallery.w116.org/dl/9789-4/Completed+RH+Cam.jpg)

This shows the completed right hand cam tower with new chain, sprocket, slider, tensioner and tensioner slider all visible. Also visible are new plastic oiler fittings attached to the steel lines that run above the camshafts and lubricate them - mandatory replacement for only a few dollars more.

(http://gallery.w116.org/dl/9795-3/Completed+Job.jpg)

And here is the completed job - just needs the ancillaries and radiator put back again.

The engine was quite different after the chain replacement - a lot of extra horsepower came from getting the timing right - total cost about $600 - 2 years ago. (original parts from Main agent were quoted at about $2300).

Please do this to your own 3.5 and 4.5 motors before they expire.

6.9 motors apparently have a ratcheting chain tensioner and are not prone to the same risk of instant and unannounced disaster as the smaller motors.


Bill



Title: Re: 450 - M117 Timing Chain Replacement
Post by: oscar on 21 April 2007, 11:44 AM
Bill,

This is a fantastic post.  I meant to say so the other day but this kind of info is what this place is all about.  If only I saw this and some other posts regarding this job earlier, I could have saved myself some labour costs.

When my mechanic first mentioned my chain was stretched and he wanted to change it, I said ok.  Why not.  The rocker covers were off and he showed me the chain saying that it was worn.  I couldn't tell, it looked exactly like yours.  But it made a difference and there's peace of mind knowing how old the chain and slides are now.

Were you going to replace the oil tube parts as well?
Title: Re: 450 - M117 Timing Chain Replacement
Post by: Tomi on 21 April 2007, 01:24 PM
great post and good pics.
its always so terrifying to drop something in that hells pit and this makes all these precautions to be good practice.
It seems that the old chain is not the original as it has the link (the original was endless) this is a good sign for that the links do actually work. This is an endless debate on how to securely connect the chain together. some say that the only way is to stamp it. well, I guess the link works but it should be directed so that the open end is opposite the chain movement direction.

Another question is that after installing a new chain do all the 3 marks align. In my case the right cam was a bit off or before. i think this could be caused of the chain not being stretched enough initially, but in time it should align better.
Title: Re: 450 - M117 Timing Chain Replacement
Post by: WGB on 21 April 2007, 08:27 PM
Hi Oscar,

I did replace the plastic oil connecters as well - they are in two packets in the centre of the first photo and I think only cost about $10 to $20 although there seemed to be no real brittleness in the originals.

Hi Tomi,

No the three timing marks didn't quite match up at the end - I can't remember but I think it ended up about 2-3 degrees ATDC at the finish.

It would have required replacement of the crankshaft sprocket to get it all back in alignment completely and at this stage it was not part of the agenda. The engine ran much more smoothly after this change and seemed to pick up a lot of horsepower.

Bill
Title: Re: 450 - M117 Timing Chain Replacement
Post by: oscar on 21 April 2007, 08:49 PM
Quote from: WGB on 21 April 2007, 08:27 PM
Hi Oscar,

I did replace the plastic oil connecters as well - they are in two packets in the centre of the first photo and I think only cost about $10 to $20 although there seemed to be no real brittleness in the originals.


Ahh so they are. Pays to look in detail  ;D  I thought they were white when new, hence I didn't notice them (let alone read the picture tags)



Quote from: WGB on 21 April 2007, 08:27 PM
Hi Tomi,

No the three timing marks didn't quite match up at the end - I can't remember but I think it ended up about 2-3 degrees ATDC at the finish.

It would have required replacement of the crankshaft sprocket to get it all back in alignment completely and at this stage it was not part of the agenda. The engine ran much more smoothly after this change and seemed to pick up a lot of horsepower.

What about offset woodruff keys?  I remember seeing them at autohausaz.   I doubt you'll try now since you've got it all going again but theoretically, if you were to take the covers off again and replace a chain down the track, could these help?
http://www.autohausaz.com/search/product.aspx?sid=3ojvm545ses5lb55qzzyh145&makeid=800016@Mercedes&modelid=1194847@450SEL&year=1978&cid=20@Engine%20Parts,%20Seals%20%26%20Gaskets&gid=5519@Woodruff%20Key (http://www.autohausaz.com/search/product.aspx?sid=3ojvm545ses5lb55qzzyh145&makeid=800016@Mercedes&modelid=1194847@450SEL&year=1978&cid=20@Engine%20Parts,%20Seals%20%26%20Gaskets&gid=5519@Woodruff%20Key)



EDIT:  Another question WGB   -   Did you by chance pull apart the old chain tensioner?   Any chance of having a look of what's inside and how has it worn?  Is it just the tip that's worn down or is there a spring inside that has weakened or did you replace it for peace of mind? 
Cheers
Title: Re: 450 - M117 Timing Chain Replacement
Post by: WGB on 21 April 2007, 11:47 PM

Good Point Oscar,

I have seen the offset woodruff keys in a Chilton's manual and in the Handbook I think.

If I ever pass that way again I'll measure and think about it - wouldn't be hard to put them in, even now.

I don't know how much difference 1 or 2 degrees make - certainly 10 degrees makes a big difference.

I still have the old tensioner and will pull it apart at some stage and see if I can see what is worn.

I didn't even consider doing the job without replacing the tensioner so didn't pay much attention to it other than there is a difference betwen the Euro tensioner and the Australian one (Extra pipe fitting for some reason on the Ozzie one).

Certainly the new one took a lot more effort to compress than the old one.

Bill

Title: Re: 450 - M117 Timing Chain Replacement
Post by: oscar on 22 April 2007, 12:24 AM
Quote from: WGB on 21 April 2007, 11:47 PM
I didn't even consider doing the job without replacing the tensioner so didn't pay much attention to it other than there is a difference betwen the Euro tensioner and the Asutralian one (Extra pipe fitting for some reason on the Ozzie one). Certainly the new one took a lot more effort to compress the new one rather than the old one.

Something else I noted whilst looking for pics was two types of tensioners, with and without smog stuff attachment. That's what the extra pipe connection is for.  Compare these two shots from http://www.mercedes-benz-parts-direct.com/epc-items.asp (http://www.mercedes-benz-parts-direct.com/epc-items.asp)

Anyway, it's good to know the different feel and strength of the new tensioner compared to the old one.  Something I've learnt from your posts is regarding when the chain breaks or guides shatter.  I always thought it happened at speed but your descriptions of what the chain does on startup  has me believing the opposite now.  It's been stated by yourself and others about the vulnerability of the chain and guides upon starting.

(http://img225.imageshack.us/img225/9525/withoutsmogconnectiongg4.jpg)(http://img204.imageshack.us/img204/3476/withsmogconnectionqz5.jpg)
Title: Re: 450 - M117 Timing Chain Replacement
Post by: WGB on 22 April 2007, 01:31 AM
I don't think the problem occurs at high speed as the tensioner should be under oil pressure no matter how worn it is.

I have seen postings in the forum atwww.mercedesshop.com (http://www.mercedesshop.com) of peoples experiences with chains and they all talk about startup or startup and manouvreing in their own driveway at low speed. The engine suddenly stops with a bang and on opening the bonnet the camshaft towers have broken through the camcovers when valves have kissed pistons. It's almost like the cam towers are like fuses and let go to save more expensive damage to pistons, rods and crankshafts.

The sliders and chain are always blamed but I think the chain thrashing around with a loose tensioner sounds more realistic .Then when a brittle slider breaks it can get caught between chain and sprocket and cause the chain to jump.

My sliders were very old and the full chocolate colour which is what they become when due for a change but they were not deeply grooved nor overly brittle.

What was brittle was the plastic insert lining the guide attached to the chain tensioner. This is a light grey/green colour and can be seen in the photograph of the parts with the part No 117 052 00 83 written in texta on the surface.

This is an interference fit on the metal guide with lugs in the plastic that snap and hold it into place - the one in my car was almost black and broke up into a number of small pieces when I tried to remove it.

Bill
Title: Re: 450 - M117 Timing Chain Replacement
Post by: SELfor50 on 22 April 2007, 05:37 PM
Hey Mate,

i did have a look at this post over the weekend - just didn't have time to reply as had to help a mate move house.

You're TRUE BLUE!!
This is possibly one of the best pieces of advice i've ever seen on the internet!!!
I haven't done much work on cars, but with the right prep work i'm gonna give this ago. 
I'm ordering the parts this week and will hopefully get it done next weekend.

Other than the step by step guides and tips here - is there any other major things that i should know before doing this??

Title: Re: 450 - M117 Timing Chain Replacement
Post by: WGB on 22 April 2007, 07:52 PM
Hi SELfor50,

Have a go and take some photos and share them with us.

Just don't drop any bits into the motor and make sure you pull a couple of rotations through cleanly on the crankshaft bolt when you're finished before starting her up.

The hard bits are pulling the pins on the sliders and then pulling the new chain through slowly.

If you want to see a much better pictorial spend US$24.95 and go towww.pindelski.com (http://www.pindelski.com) - he has a step by step photographic run through with explanation, of changing the sliders and then pulling through the chain - but you have to buy a subscription and it is a 126 site.

He changes a 560 chain but it is exactly the same.

If you want any advice put it on the site but I will be away for a few days with my wife from Thursday til Monday and internet reception may be patchy and marginal - depends whether my new NextG card will arrive before I leave with ANZAC Day and all.

My E-mail is on the site and if you want to send me a message I'm happy and it may be more likely to reach me.

Best of luck and go slow and careful.

Bill
Title: Re: 450 - M117 Timing Chain Replacement
Post by: SELfor50 on 23 April 2007, 01:11 AM
Word, and Word.

I'll post the photo's when i'm done.

Cheers Mate!

Title: Re: 450 - M117 Timing Chain Replacement
Post by: s class on 24 April 2007, 03:51 AM
Excellent work Bill.  Thanks for taking the time to share this with us. 

I see you replaced 3 guides plus the tensioner rail lining, all at the top of the engine.  Are there not other guides at the bottom of the motor?  I presume though they might be difficult to get to without removing the timing cover. 

What brand of chain did you use - you said not MB dealer.  Does anyone have thoughts on aftermarket chains?  I need to do this in my 450SL.  I am so worried about the state of my chain et al that I haven't been driving the car.

Ryan
Title: Re: 450 - M117 Timing Chain Replacement
Post by: WGB on 24 April 2007, 04:36 AM
The chain is an JWIS which is one of the original Manufacturers and the tensioner is a FEBI (Ferdinand Bilstein).

The boxes are in the first picture.

Good quality and purchased from M-B spares in Canberra Australia.

I will have all the original receipts and may even have the original quote form the main agent for the parts (Approx $2300) Vs non-OEM parts for about $700.

You cannot remove the bottom slider without taking the front off the motor - which was not the point of the exercise.
I think there is only one on the left side of the motor as the long tensioner slider does the job on the right side.

Bill
Title: Re: 450 - M117 Timing Chain Replacement
Post by: 116.025 on 24 April 2007, 07:50 AM
Bill, thanks for this excellent post, as I am about to embark on this job(minus cam sprokets) myself after discovering on Saturday that my tensioner on the 350SE was totally dead.  If some of the other 350 owners would like, I can post the part numbers for my 116.985 so they don't have to hassle with looking it all up.  After reading through your description of the job again, I was left with one question: you mentioned filling the new tensioner with oil...how did you do that?  I wasn't quite seeing it and didn't want to miss a vital step.

And since something on my 280 went awry, I might just slap a new tensioner on there in the next day or two(so I can quit borrowing my dad's SDL) and get the chain, guides, et al next weekend since I'm out of town this weekend.  Anyone know if it would have negative effects to put a new tensioner on without the rest for a few days?
Title: Re: 450 - M117 Timing Chain Replacement
Post by: WGB on 24 April 2007, 08:50 AM
Quote from: 116.025 on 24 April 2007, 07:50 AM
I was left with one question: you mentioned filling the new tensioner with oil...how did you do that?  I wasn't quite seeing it and didn't want to miss a vital step.

Anyone know if it would have negative effects to put a new tensioner on without the rest for a few days?

I don't know if you have an Oz or Euro motor - the Euro tensioner has three holes you can see in the previous tensioner photos - two for mounting bolts and one is an oil hole. Immerse it in oil and make sure it is really full before bolting it up with a new gasket. I don't think it is possible to work the piston without a large amount of compression force but I can't really remember. Bolting it up compresses the piston and will push some of the oil out and dampen it before the oil pressure takes over when the engine starts.

Unless your chain is really worn a new tensioner should be adequate for a short term run but you will need two gaskets to make sure the final job keeps all the oil in when you are finished - so as not to re-use a gasket.

Two points of care not mentioned - to replace the sliders you will have to remove the sprockets whether you change them or not, just to give adequate clearance for removal and replacement of the slider pieces. You should use cable ties to hold the chain in position on the sprockets, then unbolt the sprockets while using a screwdriver through the sprocket hole to steady it and then keep the chain in tension so that it cannot move on the crankshaft sprocket .

The other point is that to remove the tensioner slider the lower pivot point has to be released. It is housed inside a cap low on the front of the motor. The cap is unscrewed and inside is a hollow pin which can be extracted by slipping a phillips head screwdriver into it and jiggling the tensioner arm and the screwdriver until it appears - may be worth tying a piece of wire to  the top of the slipper so that it doesn't drop too far but frommemory it can't drop right down.

I will place this in the main body of the post for easy reference

Bill
Title: Re: 450 - M117 Timing Chain Replacement
Post by: oscar on 24 April 2007, 09:32 AM
Quote from: 116.025 on 24 April 2007, 07:50 AM
  If some of the other 350 owners would like, I can post the part numbers for my 116.985 so they don't have to hassle with looking it all up. 

Yes please ;D  I assumed everything would be the same for the 450 as for the 350 except the length of the chain.  I'd also like to hear how you go sourcing 350 parts if they are different as no US parts sites have the 350se/l on their database.  My guess is that r107 350slc or the w108 3.5L engine may share the same parts. 

I'm thinking of changing my tensioner too, as I have no record of it being changed.  Just upper slides and chain and oil rail plastic bits.
Title: Re: 450 - M117 Timing Chain Replacement
Post by: 116.025 on 24 April 2007, 10:11 AM
Quote from: WGB on 24 April 2007, 08:50 AM
I don't know if you have an Oz or Euro motor - the Euro tensioner has three holes you can see in the previous tensioner photos - two for mounting bolts and one is an oil hole. Immerse it in oil and make sure it is really full before bolting it up with a new gasket. I don't think it is possible to work the piston without a large amount of compression force but I can't really remember. Bolting it up compresses the piston and will push some of the oil out and dampen it before the oil pressure takes over when the engine starts.

Euro...or more precisely, probably middle eastern, since they guy I bought it from had imported it and was middle eastern, and I keep finding sand under stuff on the engine...Thanks, now I understand what you meant about filling it with oil.

Quote from: WGB on 24 April 2007, 08:50 AM
Two points of care not mentioned - to replace the sliders you will have to remove the sprockets whether you change them or not, just to give adequate clearance for removal and replacement of the slider pieces. You should use cable ties to hold the chain in position on the sprockets, then unbolt the sprockets while using a screwdriver through the sprocket hole to steady it and then keep the chain in tension so that it cannot move on the crankshaft sprocket .

Hmm, interesting.  If I have to remove them anyway, I might just replace them.  Regarding keeping the teeth and keyway position in alignment, was match-marking the sprockets and chain how you accomplished that?

Quote from: oscar on 24 April 2007, 09:32 AM
I assumed everything would be the same for the 450 as for the 350 except the length of the chain.  I'd also like to hear how you go sourcing 350 parts if they are different as no US parts sites have the 350se/l on their database.

Oscar, you may be correct, I didn't bother to check the M117 microfiche to verify.  I'm sourcing 350 parts by looking them up on the microfiche I bought off of my parts guy (so I can look up Euro, Oz(I think), and USA parts for everything from 111s to 140s) and passing the parts numbers along.  He's also got a deal going where for $100/yr I get parts at his cost.  PM me if you want details on how to get in on it, I think even with shipping you guys down under might be able to save some money.  Here's the list so far, I realized this morning I need to expand it(as I forgot chain, valve cover gaskets, etc), I'll update later:
Cam oiler kit 116 586 02 18 (x2, of course) threw this in as a bonus, since I'm replacing them, too  ;)

Chain guides 116 052 17 16 (x3)

Tensioner Rail 116 050 28 16

Tensioner 116 050 16 11 (Euro)

Oscar, you'll need to check your engine number, being a '73, yours won't be a 116.985, I don't think.  Some of the 116.98x (I think it was 982 and 983) had some footnotes leading to different part #s.  If you check your engine #, I'll verify the tensioner part # for you...engine Oz or Euro?
Title: Re: 450 - M117 Timing Chain Replacement
Post by: oscar on 24 April 2007, 10:24 AM
Thanks Chad,

I'll have to check it tomorrow, I should know this off hand.   I'm sure it's 982 but I'll PM you tomorrow.  Cheers.
Title: Re: 450 - M117 Timing Chain Replacement
Post by: Tomi on 24 April 2007, 11:07 AM
hi, 2 comments:

I didnt have to remove the cam sprockets to replace the 3 new rails. One of them was a tight fit though.

Installing the tensioner is a really fun project. The spring is quite stiff specially when filled with oil. The only way I could do it, was to use longer screws to start and then switch to the shorter original screws one by one once they are within reach.

regards
Title: Re: 450 - M117 Timing Chain Replacement
Post by: koan on 24 April 2007, 04:18 PM

If anyone is considering using the excellent photo guide and additional posts as an aid in replacing their M100 6.9 chain there is one significant difference.

The 6.9 chain tensioner is a different design to the 4.5, it has a ratchet mechanism to avoid the startup problems mentioned. When removed it will move to full extension and must be pulled apart and reassembled on the engine.

koan
Title: Re: 450 - M117 Timing Chain Replacement
Post by: WGB on 25 April 2007, 03:43 AM
Quote from: 116.025 on 24 April 2007, 10:11 AM

Quote from: WGB on 24 April 2007, 08:50 AM
Two points of care not mentioned - to replace the sliders you will have to remove the sprockets whether you change them or not, just to give adequate clearance for removal and replacement of the slider pieces. You should use cable ties to hold the chain in position on the sprockets, then unbolt the sprockets while using a screwdriver through the sprocket hole to steady it and then keep the chain in tension so that it cannot move on the crankshaft sprocket .

Hmm, interesting.  If I have to remove them anyway, I might just replace them.  Regarding keeping the teeth and keyway position in alignment, was match-marking the sprockets and chain how you accomplished that?


When I received the quote for the parts from The Main Agent - Diesel motors the Sprockets were $300+ each but I purchased them from M-B spares in Canberra at about $80 each (actually 70 something dollars from memory)
More accurate timing and less initial wear on the new chain - the originals looked OK on the motor but when compared with a new one there was significant wear.

You will see various marks with white paint and black Texta on the pictures  of the chain and sprockets - this was to keep the alignment when changing the sprockets over. The only important part is that the chain is kept taut between crankshaft sprocket and where it appears at the top of the head on both sides when unbolting them and dealing with each side one at a time.

Tomi said that he only had clearance problems with one slider when not removing the sprockets - looked a tight fit to me and I was replacing the sprockets anyway.

I used the pictorials on www.pindelski.com (http://www.pindelski.com) as my guide and he says to remove the sprockets when changing the guides. They are not hard to remove and may help save dropping something into the bottomless depths - although it adds complexity if not changing the sprockets.

Bill
Title: Re: 450 - M117 Timing Chain Replacement
Post by: SELfor50 on 01 May 2007, 10:13 PM
Bill,

Thanks for your priceless advice!!!  I was gonna tackle my timing chain myself with a mate, but decided against it.

My mechanic who services the vehicle no problems didn't wanna assist with the timing chain as he didn't want it hanging over his head if he stuffed it....so i'm gonna take it to MB spares.  They said $1200 will cover it and that's only if the cam sprockets need doing as well, otherwise it should be a little under that.

Is there anything else you can recommend doing while it's there to increase the HP / performance at all?
My budget goes up to $1500 total.  So i guess for an extra $3-400 there's not much that would increase performance.
I've already given it new leads, sparkplugs, dizzy cap ($160?!?!)...  Should i just save the cash and spend it on a new exhaust / extractors?

Cam.
Title: Re: 450 - M117 Timing Chain Replacement
Post by: WGB on 02 May 2007, 05:27 AM
I would save the money for the next piece of excitement eg waterpump,radiator, brakes, exhaust etc. 3 or 400 dollars will not last long.

I would always trade reliability so that the available performance could be used to the full before I tried increasing what I had.


Bill
Title: Re: 450 - M117 Timing Chain Replacement
Post by: SELfor50 on 03 May 2007, 01:09 AM
Word...
Title: Re: 450 - M117 Timing Chain Replacement
Post by: lube on 13 July 2011, 04:17 AM
This is a most excellent thread, possibly the best M117 timing chain guide on the net.
I have one question: what is the spec of the bolt used to remove the guide rail pins?
I also found this description (http://w126-archiv.mercedesforen.de/index.php/Gleitschienenwechsel_beim_M116/117) of the removal tool, but he also neglects to specify the thread. 
I'm hoping someone who's done the job might be able to tell me so that I can assemble all of the tools necessary before starting the job.
Cheers.
Title: Re: 450 - M117 Timing Chain Replacement
Post by: WGB on 13 July 2011, 05:57 AM
Thank you lube for the compliment - the size of the bolt required is M6 with the length dependant on what you are using to pull against.

I did this job about 5 years ago and posted it some 4 years ago.

I have also posted a pictorial on doing my 6.9 chain which I did about three years ago and used Visegrips rather than a packet of cable ties.

6.9 Chain replacement (http://forum.w116.org/mechanicals/pictorial-6-9-timing-chain/)

Here is a picture of a Rail Guide Puller that I have subsequently purchased off ebay.

(http://i257.photobucket.com/albums/hh219/WGB_album/PinPuller.jpg)

Basically it has an M6 thread which is screwed into the pin and the outer has a ball bearing in it to reduce friction when you tighten it up.

Both these jobs were done with the cam followers in place which means that you need to be slow and methodical and use plenty of force to grip the chain and prevent it sliding over the RH cog.

Latterly I made one of these valve lifters from an M117 plan and if the Cam followers are removed before changing the chain it makes the job much simpler and less nail biting.

Here is a copy of the lifter I made

(http://i257.photobucket.com/albums/hh219/WGB_album/M117Valvespringcompressor.jpg)

And here is a copy of the plan that was used to make it.

(http://i257.photobucket.com/albums/hh219/WGB_album/117Valvespringcompressorplan.jpg)

Best of luck and you will have done a great service to the longevity of your car if you have a healthy chain and tensioner.

Bill
Title: Re: 450 - M117 Timing Chain Replacement
Post by: Big_Richard on 13 July 2011, 06:56 AM
TJ did the chain replacement on my 6.9.

must of done it properly as its still going all these years later.

I do recall though, slicing my finger down to the bone on the razor sharp (i think) grooves in the tensioner rail that the chain runs on.

I didn't fancy removing the water pump a second time so I demanded all the original guides left in place.

Foolish decision ? i don't know, i don't really drive the car often enough to warrant the extra effort required.
Title: Re: 450 - M117 Timing Chain Replacement
Post by: lube on 14 July 2011, 06:04 AM
WOW that is fantastic information. Thanks for the bolt spec, now I can just get a selection of different lengths to make up the tool on that German page. thanks for the info on the ready-made tool. I'd seen it before and although I don't mind spending money on MB parts I'm always looking to save a few quid so I'll prob go with the home made tool, unless you can see any disadvantages aside from ease of use?

I'm planning to do the job this weekend so will post back if I get stuck.

BTW I recommended this thread to be a sticky on the Benzworld R107 forum, but for some reason they still prefer the peachparts page!!!

Thanks also for the other link. Gotta love that 6.9. One day...

I also had another question that so far no one has been able to answer. I understand that to do the lower guide you either have to remove the sub-frame or the engine (assuming the 116 is similar to the 107?). Now a highly experienced mechanic friend of mine said that it is possible to jack the engine up a bit (but not remove it) in order to remove the oil pan to remove the timing cover to get to the lower guides. Anyone have any experience of this? I know the lower guides rarely fail but I always like to do things properly if possible!

Cheers.
Title: Re: 450 - M117 Timing Chain Replacement
Post by: WGB on 14 July 2011, 07:36 AM
If you are going to this level it would be worthwhile replacing the crankshaft sprocket as well to get the timing absolutely spot on.

Bill
Title: Re: 450 - M117 Timing Chain Replacement
Post by: TJ 450 on 14 July 2011, 10:18 AM
AFAIK the 107 versions are different, in that they have a one piece cast sump assembly like the M100. The sump must be removed in order to remove the timing cover, as there is one oil pump mounting bolt that must be removed from underneath, as well as the oil pump chain.

On the 116, you can get away with just removing the pressed lower sump pan to access the bolt if I remember correctly.

Jacking up the engine should work, as I believe "s class" did this successfully with one of his M100s.

I concur with Bill, you might as well replace everything while you're in there (the oil pump should be fine though). It's a good opportunity to clean up the front of the engine and fix any oil leaks that may be present too.

Tim
Title: Re: 450 - M117 Timing Chain Replacement
Post by: lube on 15 July 2011, 01:26 AM
Interesting thanks Tim. Yes it's a one piece sump. I think the main problem is getting to the sump bolts, so I was thinking I could jack the engine up, undo the sump bolts, lower it again, remove the sump, then do all the rest.
No idea if this will work but I might give it a shot.

Cheers.
Title: Re: 450 - M117 Timing Chain Replacement
Post by: Gerard on 15 July 2011, 06:37 AM
I did this job  last Christmas on my 450, chain , top guides, cam sprockets and tensioner.

My method was slightly different in that I used cable ties instead of the vice grips.  Just buy a bag of 100 or 200, and using 2 cable ties to hold the chain to each sprocket, snipping one tie and adding a new one every 1/4 turn or so of the sprocket.

I turned the engine using the crankshaft nut and T-bar,  and extended socket.  I loosened the plugs (cant remember if I removed them altogether) but I didnt remove the valve lifters, so be careful when turning as the crank can "overshoot".

As a word of warning, my upper guides were very brown, and the end of one had broken off and was rattling around in there, with teeth marks on it from the sprocket :o.

Blessed there wasnt more damage.  I had meant to re-check the chain this winter, and purchase a set of offset woodruff keys to improve the timing, but alas, the car has been sold.

Gerard

(http://i656.photobucket.com/albums/uu290/gmcgrana/Image0073.jpg)

Title: Re: 450 - M117 Timing Chain Replacement
Post by: TJ 450 on 15 July 2011, 07:43 AM
Yikes, that has run through under the chain. Lucky there wasn't a catastrophe. :o

I've done the job on a few cars now, including MT's as mentioned. Once it is done properly, the peace of mind is very rewarding.

Tim
Title: Re: 450 - M117 Timing Chain Replacement
Post by: lube on 19 July 2011, 05:16 PM
Just thought I'd update with my progress...
I decided to do one side of the engine at a time, as follows:
Left side (with the engine in front of you) first:
Rotate engine so that master link (if present) is accessible on that side.
Mark cam + chain.
mark position of cam.
Plug gap with rag so nothing can fall down there.
Use cable ties to secure chain in tension, without obstructing access to guides.
Loosen nut on camshaft, putting wheel nut wrench handle through holes to stop cam turning.
Remove master link.
Remove cam gear (lightly tap off with hammer).
remove tensioner.
Remove tensioner rail (pin should slide out, don't worry you can't push it through!)
Remove tensioner rail.

That's where I'm at so far. Have a look at my pictures to see how I used the cable ties, and check out the state of my tensioner rail! At least the tensioner was doing it's job.

(https://lh3.googleusercontent.com/-NUK5V3ZX62Q/TiX678wK1gI/AAAAAAAACtg/g0EIJhs0JPQ/s640/19072011248.jpg)

(https://lh4.googleusercontent.com/--aZBIHRZ_s4/TiX67xOfFCI/AAAAAAAACtk/MtdTZl3tPzs/s640/19072011247.jpg)

(https://lh3.googleusercontent.com/-WyL8YqioClo/TiX68mD_fRI/AAAAAAAACto/dZw8CrFW8FI/s640/19072011249.jpg)

(https://lh6.googleusercontent.com/-CUuJCkKxxTs/TiX683tJFOI/AAAAAAAACts/_aT4bSAlaEE/s640/19072011250.jpg)

(https://lh5.googleusercontent.com/-8AesPXasi6o/TiX69CmLgbI/AAAAAAAACtw/fhlTN8q6aps/s640/19072011251.jpg)

(https://lh6.googleusercontent.com/-oxlZfuv7boo/TiX69ZQ7wcI/AAAAAAAACt0/pxUtxvsInDY/s640/19072011253.jpg)

(https://lh6.googleusercontent.com/-QWic9AC17J0/TiX69hY6q_I/AAAAAAAACt4/s-dr48xUORg/s640/19072011252.jpg)

(https://lh3.googleusercontent.com/-GHin0Y0lGa4/TiX6-ZiE8pI/AAAAAAAACt8/eohoDaRaRhI/s640/19072011245.jpg)

(https://lh6.googleusercontent.com/-c_nomn_wEyo/TiX6-kMOwfI/AAAAAAAACuE/h6dyE4CY1ao/s640/19072011254.jpg)

I also used a magnet taped to a piece of tube to stop anything going anywhere near the hole just in case I fumbled!

Question: Does anyone think I should replace the slighty worn tensioner/banana rail, if so why? With the new plastic slider fitted it seems fine.

Also would anyone recommend replacing any bolts anywhere as good practice? Also what about the sprung washers on the cams?

Cheers.
Title: Re: 450 - M117 Timing Chain Replacement
Post by: WGB on 19 July 2011, 09:33 PM
Scarey what hides in these old motors and how long they actually hold together following decades of minimal maintenance.

If there is a spare unmarked rail easily accessible I would take it but I wouldn't foresee any problems using the old one with a new lining as the load is spread over a wide area.

Just be careful if you haven't removed the cam followers (fingers)   not to lose the correct camshaft to chain alignment and then try to turn the motor .

I think from memory I kept the engine with all the marks at TDC and then released the chain to change the sprockets and sliders.

The engine will safely turn with the chain jumped one sprocket but if there is a lot of carbon there may be some interference develop with a second sprocket tooth jump.

It looks like you replaced the chain first which is fine - the two jobs need to be treated as being almost separate items i.e. chain replacement vs replacement of cogs and sliders.

Thanks for the photos and hope it continues to go well.

Bill 
Title: Re: 450 - M117 Timing Chain Replacement
Post by: s class on 20 July 2011, 02:34 AM
Wow that tensioner rail is worn. 
Title: Re: 450 - M117 Timing Chain Replacement
Post by: s class on 20 July 2011, 02:36 AM
Quote from: TJ 450 on 14 July 2011, 10:18 AM
AFAIK the 107 versions are different, in that they have a one piece cast sump assembly like the M100. The sump must be removed in order to remove the timing cover, as there is one oil pump mounting bolt that must be removed from underneath, as well as the oil pump chain.

On the 116, you can get away with just removing the pressed lower sump pan to access the bolt if I remember correctly.

Jacking up the engine should work, as I believe "s class" did this successfully with one of his M100s.

I concur with Bill, you might as well replace everything while you're in there (the oil pump should be fine though). It's a good opportunity to clean up the front of the engine and fix any oil leaks that may be present too.

Tim

Yes, I did remove the entire sump pan off one of my 6.9's with the enigne in situ.  But it was difficult.  I had to lig the enigne basically as high as I could with the engine crane, and remove the aircon compressor, brackets etc. 
Title: Re: 450 - M117 Timing Chain Replacement
Post by: lube on 20 July 2011, 03:24 AM
Thanks Guys,

I suppose I could fill the gap in the banana rail with JB weld two part epoxy and then smooth it off (seeing as it's ally I'd get a good bond), but I can't see that it's make any difference. If it ever gets that worn again then obviously the gap will cause more wear on the part in contact with the chain rollers.

It's not shown in the picture but I've marked the alignment of the cam relative to the engine and the chain relative to the cam sprocket, so I'm hoping that should be sufficient.

Once it's all back together I assume that a) checking the engine turns smoothly by hand, and  b) making sure the timing marks all line up at TDC will ensure that I haven't skipped any teeth?

In fact I'm going to do the chain last, so my order of work is: left side, right side, then chain.

Thanks for the info on the oil pan. When I'm all finished, before fitting the chain and putting the ancillaries back I may jack the thing up and take a look underneath, see if the lower guides are worth a shot.

Cheers.
Title: Re: 450 - M117 Timing Chain Replacement
Post by: lube on 20 July 2011, 04:01 PM
OK made some progress today, got the LHS all done no problem. Replaced all guide rails.

Unfortunately when undoing the chain master link on the RHS I forgot to undo the tensioner, and it seems that it pulled the chain around a couple of teeth. Now the two cams and the crank (obviously) are all still in the same position (marked on all) when the chain came off. I'm assuming the relative position of the central sprocket behind the water pump doesn't matter, therefore I was planning on simply pulling the chain around the LH cam gear in order to take up the slack, so in the end the master link will be two teeth clockwise from where it started (making sure the cams and the crank don't move).

Does this sound ok?

My other question is about the tensioner itself. People suggest filling this with oil prior to installation. I filled it (patiently!) through the small hole until there were no more air bubbles. Is this the right way to fill it?

Cheers.
Title: Re: 450 - M117 Timing Chain Replacement
Post by: WGB on 20 July 2011, 07:26 PM
Yes - removing the tensioner is one of the earlier processes in the system and if the tension is removed from the chain it is not necessary to split the chain before working on removing sprockets and sliders.

The splitting of the chain can be left until the chain is actually replaced.

Another issue will be getting the correct timing when you have the new chain in place

If you have the timing marks all lined up there is a notch on the distributor body at which the rotor is supposed to point so that it is roughly correct for initial set up.

You will have to lift the edge of the internal plastic shield to see it as is shown in this picture.

(http://i257.photobucket.com/albums/hh219/WGB_album/No1MarkonDistributer.jpg)

Here is the notch on a 6.9 distributor which should be the same as a 117.

Bill

P.S - I have changed the pictorial and added a comment about removing the tensioner first.
Title: Re: 450 - M117 Timing Chain Replacement
Post by: lube on 21 July 2011, 02:09 AM
Thanks Bill,

So you're saying I should have kept the chain together - that would have been easier! I know I should have removed the tensioner, I had just put it back on whilst rotating the engine to get the master link to the RHS. Oh well.

So in my current situation as long as the two cams are aligned with the crank I have nothing to worry about right? The distributor is off, I will re-align it when I put it back later. For now I just want to get the old chain done up and check that the engine is correctly aligned before I go for the chain replacement.

Thanks a lot for all your helpful advice.

Cheers,

Lube
Title: Re: 450 - M117 Timing Chain Replacement
Post by: WGB on 21 July 2011, 02:56 AM
I would put your master link back together again on your old chain - make sure the two cam and the crankshaft timing marks all line up with the tensioner blade and new liner in place but do not put the tensioner itself back yet.

Gently pull the engine through a complete cycle couple of times to make sure there is no interference (assuming your cam followers are in place) and then replace the chain - again pulling it through a couple of revolutions to make sure there is no interference.

At this point everything will appear to line up and then put the tensioner back in - filled with oil (May need some longer than normal starting bolts to pull it in and then replace with the standard bolts).
Usually the tension will change the chain position a little and what initially lined up will end up with 2 or three degrees of apparent chain stretch caused by wear in the cranshaft sprocket.

I would again pull the motor through a couple of revolutions with the chain tensioned and check you are happy and then put on the dissie and all the ancillaries.

Bill
Title: Re: 450 - M117 Timing Chain Replacement
Post by: lube on 21 July 2011, 03:08 PM
Hi Guys,
Just another update, and  your opinions solicited please:
Got new chain on fine, as well as the tensioner on. The engine turns as smoothly as before, BUT...

As it is now, when the LHS cam is at the TDC mark the flywheel measures about 6-7 degrees past TDC. Before I started the job I measured about 8 degrees past TDC at the crank with the LHS cam marks aligned (I never looked at the RH cam marks). Now everything is back together and the tensioner installed the RH cam marks are not exactly aligned, but just over 1mm off (see pictures below). You can see I marked on the RH cam where the mark would be if I was one tooth off, and I think I'm ok. If anyone's interested 1 tooth would put you 4.3mm from the cam mark.

1 and a bit mm on the cams is around 3 degrees which means about 6 degrees at the crank, so this makes sense. It seems that the crank and the RH cam are aligned as thy should be, but that the LH cam is slightly retarded. Could it be that the new chain and tensioner is putting it under extra tension thus causing it to be slightly retarded?

I did also notice that there is much less slack in the chain between the two cams with the new chain installed.

Does this sound ok? 7 degrees off TDC with a new chain seems a lot to me. I suppose it must be wear in the crankshaft sprocket. Is it worth installing a woodruff key on the RH cam?

Thoughts? Below are the photos...

Edit: I just noticed that my current situation with new parts is almost identical to the photos at the top of this thread. Bill,did did the new parts cure the cam misalignment? Also, I should state that all my LH, RH references are looking from in front of the engine.

Cheers,

Lube

LH Cam: Marks aligned.
(https://lh6.googleusercontent.com/-zhtLS5Pejko/TiiGazMiEpI/AAAAAAAACuw/9X59h-Ewy8M/s640/21072011261.jpg)

Crank: ~7 degrees off.
(https://lh3.googleusercontent.com/-wsddmRtMxpY/TiiGbBVaTyI/AAAAAAAACu0/Tzj-XFoEYtw/s640/21072011264.jpg)

RH Cam: 1mm off.
(https://lh4.googleusercontent.com/-lg6qbMhLPnQ/TiiGbyF4R0I/AAAAAAAACvE/6_WphRqCtCM/s640/21072011268.jpg)
Title: Re: 450 - M117 Timing Chain Replacement
Post by: lube on 23 July 2011, 12:51 PM
OK another update:
I removed the tensioner and lined up the RH cam mark and read about 3 degrees before TDC on the flywheel. I then pulled the LH cam back slightly so that it lined up with its mark, then did up the tensioner. Doing this caused the LH cam to be pulled back very slightly.
So I think it's just a case of the new tensioner slightly over tensioning the chain, causing the LH cam to pull back slightly from the LH cam mark. I'm sure after a few thousand miles it will be slightly looser and the marks will be in perfect alignment. I can't think of any other explanation as to why the cams should be misaligned with brand new sprockets and a brand new chain! Essentially this means there is about 1mm (or 5 degrees at the flywheel) of movement depending on the tension exerted by the tensioner and the amount of tension in the chain between the cams, meaning that it's probably best to get the alignment from the RH (opposite side to tensioner) cam marks.
Below are the photos I took of the final alignment.  I think it's slightly better than before. One thing I also noticed is that there is a hell of a lot more force on the tensioner rail with the new tensioner compared to the old one.
Hope this helps someone.
Cheers.

LH Cam in perfect alignment:
(https://lh4.googleusercontent.com/-0AafowY1Onk/TisJYU4_chI/AAAAAAAACvc/ma7U0cLEkCA/s640/23072011272.jpg)

2 degrees off at the flywheel:
(https://lh4.googleusercontent.com/-VUpRIh8qOvI/TisJY_bBMWI/AAAAAAAACvg/jaDRse-yfDY/s640/23072011273.jpg)

Slightly retarded at the RH cam:
(https://lh6.googleusercontent.com/-UVoDyIva6Iw/TisJYGSiIqI/AAAAAAAACvY/bCpatNB68M8/s640/23072011274.jpg)
Title: Re: 450 - M117 Timing Chain Replacement
Post by: WGB on 24 July 2011, 02:42 AM
Are you sure you have LH and RH correct - they should be as seen from the driver's seat.

Timing is taken from the RH cam and the crankshaft - LH cam mark never seems to line up exactly.

I would only test the timing after applying the tensioner pressure and after having pulled the motor through a couple of complete revolutions - as the chain needs  to seat itself on teh cogs correctly.

Bill
Title: Re: 450 - M117 Timing Chain Replacement
Post by: s class on 24 July 2011, 05:49 AM
Is it possible that you have offset woodruff keys installed?

I have replaced chains and sprockets on numerous 450/500 motors, and I typically find that with new chain and cam sprockets, the RH cam will still be approx 5 degrees late on the crank.  I normally install low value offset woodruff keys to address this.  I typically find that the left cam is timed pretty close to zero, and offset keys are not normally needed on that side. 
Title: Re: 450 - M117 Timing Chain Replacement
Post by: lube on 24 July 2011, 05:56 AM
Thanks Bill,
Yes sorry about my LH/RH references, they are all from standing in front of the engine (as in turning the engine clockwise!).
In the manual (e.g. 05-320) it doesn't mention which mark to take the timing from (LH or RH). I'm certain that the tension due to the tensioner retards the LH cam slightly, as I can see the difference before and after I bolt up the tensioner. On this basis surely it would make sense to take the timing from the RH (non-tensioner side) cam as this will be independent of the age/force of the tensioner (on the basis that the tension in the chain between the two cams is much less than the tension between the crank and the RH cam)?

S-class: thanks, that seems to be exactly my situation. My tensioner-side cam is about 7 degrees late at the crank, whilst my non-tensioner-side cam is about 2 degrees early (which I can live with). I'm pretty sure the woodruff keys were both straight. I suppose I could install a woodruff key, if it's worth it?  Why do you think it is that the tensioner-side cam is always slightly retarded?

Cheers for all your help guys. It's super useful to hear from your experience of doing this job multiple times!
Lube
Title: Re: 450 - M117 Timing Chain Replacement
Post by: s class on 24 July 2011, 12:11 PM
The right hand cam (tensioner side) will always show more retardation than the left side (assuming non-offset woodruff keys are used).  This is because :

a) there is a greater length of chain between the crank sprocket and right cam sproket than for the left side, so chain stretch has more of an impact. 

b) The idler sprocket at the bottom of the vee affects only the right sprocket

c) If the heads have been skimmed, the right side is doubly impacted.

As to c) above, if the heads are skimmed, the camshafts are located slightly lower than originally.  This means that the chain effectively has excess length (which the tensioner deals with), and the result is cam retardation.  The left cam is affected only by the loss of the deck height on the left, whilst the right cam is affected by both, due to the path that the chain travels.

You must assess the chain stretch on the right hand side (tensioner side) since this shows you the combined effect of all of the above factors.  The two cams must both be timed correctly.  It is not valid to assess cam timing with the tensioner removed, because the chain will be allowed to have some slack all along its path length.  When the tensioner is installed, and the enigne has been wound through several rotations, then the chain is taut all along, (as it is in normal engine running operation) and you can assess the actual cam timing. 
Title: Re: 450 - M117 Timing Chain Replacement
Post by: lube on 25 July 2011, 04:42 AM
OK so I'm going to go for a woodruff key as sugested by S-class, but there's a discrepancy between the shift given in the manual and the shift noted in the EPC.

According to the manual (05-215) the part numbers and corresponding crank angle corrections are as follows:
621 991 04 67  - 4 degrees (0.7mm offset on cam)
621 991 02 67  - 6.5 degrees (0.9mm offset on cam)
621 991 01 67  - 8 degrees (1.1 mm offset on cam)
621 991 00 67  - 10 degrees (1.3 mm offset on cam)

BUT according to the EPC the shifts given are half the above:
621 991 04 67  - 2 degrees
621 991 02 67  - 3 degrees
621 991 01 67  - 4 degrees
621 991 00 67  - 5 degrees

Is it that the EPC is referring to a shift in cam angle? If so that would be stange.
Can anyone confirm which parts give which shift?!! MB UK can't!

Thanks again,
Lube
Title: Re: 450 - M117 Timing Chain Replacement
Post by: s class on 25 July 2011, 05:08 AM
If you install 621 991 04 67, it will advance the cam such that a 4 degree change in angle is observed at the crank. 

Remember, 2 deg at cam = 4 deg at crank, because the crank makes 2 revolutions for every one revolution of the cams. 

Be careful though when you order these offset keys, as the often get mixed up in the parts bins.  Both the MB agents here and AutohausAZ have supplied me higher offset keys when I've ordered 621 991 04 67. 

AutohausAZ have finally admitted they are out of stock on 621 991 04 67 this week when I ordered 4 of them.

621 991 04 67 is tough to get hold of, but I have a bunch of wrongly supplied 621 991 02 67, 621 991 01 67  and 621 991 00 67 at home. 

I presume you want 621 991 02 67, I will check what Ive got and measure them up to identify them.  If I have the ones you are looking for, I'm sure I could mail them off to you. 

bear in mind that the right hand cam needs 2 x whichever value key you select, as one key is under the sprocket, and one partly under the sprocket, partly under the spacer ring. 
Title: Re: 450 - M117 Timing Chain Replacement
Post by: lube on 25 July 2011, 06:36 AM
Many thanks S-class that is exactly the info I was after. As you suggest I think 621 991 02 67 is what I need to advance the tensioner-side cam about 6 degrees or so (measured at the flywheel). I had no idea I needed two of these per cam! You have just saved me a bunch of time.
Please let me know if you have them and I will send you some beer money.
Cheers!
Title: Re: 450 - M117 Timing Chain Replacement
Post by: s class on 25 July 2011, 08:32 AM
I'll check tonight.  Only the right hand cam needs 2 keys.  The left cam takes only 1 because it doesn't have a spacer sleeve behind the sprocket. 
Title: Re: 450 - M117 Timing Chain Replacement
Post by: lube on 30 July 2011, 07:00 PM
OK so I got the offset woodruff keys from MB and measured them to check they are correct. After several minutes spent picking at the old keys with a screwdriver to get them out (whilst thinking to myself "surely MB wouldn't make it this hard") I realised the way to remove them is to tap down the far end of each key with a chisel causing the near end to pop out, which was still a bugger of a job.

Now I'm just trying to get my head around which way to put the offset keys in. As it was my RH cam (as seen from behind the wheel) was arriving at it's mark about 6 degrees after the engine had reached TDC, so it was retarded by 6 degrees, and therefore I need to install the key with the offset to the RIGHT (as seen from behind the wheel) according to position'A' in the drawing in the manual.

Am I right in thinking that whilst this will cause the RH cam timing to be correct (i.e. inlet valve about to open at TDC) my timing mark on the RH cam will still be at the same position as it is now (or as it was before I removed the straight woodruff keys) when the engine is at TDC, i.e. slightly retarded?

In other words the woodruff keys will correct the actual timing but not the alignment of the RH cam marks?

I just wanted to check as I only want to install these keys once!

Cheers,

Lube
Title: Re: 450 - M117 Timing Chain Replacement
Post by: s class on 31 July 2011, 01:26 AM
The keys will correct the actual timing, but not the timing mark. 

I use a dial gauge to assess the crank angle at which 2mm valve lift is achieved too confirm the timing is correct after I've installed offset keys. 


These descriptions are confusing in text form - but I think you are correct.  As seen from sitting in the car, the top part of the key that protrudes out of the camshaft must point towards the right.  (if the cam is positioned such that the keyways are on top). 
Title: Re: 450 - M117 Timing Chain Replacement
Post by: lube on 31 July 2011, 03:54 AM
OK great. I didn't use a dial gauge to check the 2mm valve lift point beforehand, but I'mm assuming that when it left the factory those cam timing marks would have been bang on (it's a Mercedes after all), and furthermore based on s-class's experience it sounds like my situation is typical.

I will try to check with a dial gauge afterwards just to make sure (and hope that it tells me I'm ok as I don't want to have to re-do those bloody woodruff keys!)

Thanks again for your help.

Cheers.

Title: Re: 450 - M117 Timing Chain Replacement
Post by: lube on 04 August 2011, 03:38 AM
FINALLY got everything back together, all bolts tight, all hoses connected, all connectors connected, turn the key and...nothing!
Turns out the battery died in the heat (I left it in the passenger cabin as the boot was full). B*llocks.
Charging it all night did nothing so most likely the battery water evaporated.

Managed to start it with a battery pack and all seems well. No funny noises, engines sounds/feels very smooth.

Still got a fluctuating idle problem though, but it is at least driveable. Should be getting it's MOT test today.

THANK YOU so much to everyone on this thread that helped. I sincerely hope I have added to the content of this extremely useful thread and not just added noise!

Cheers,

Lube
Title: Re: 450 - M117 Timing Chain Replacement
Post by: ptashek on 19 June 2013, 07:10 AM
Did anyone do the whole nine yards, replacing also the crankshaft gear, how does the job differ (apart from opening the timing box) in terms of aligning all the critical parts?
Title: Re: 450 - M117 Timing Chain Replacement
Post by: lube on 19 June 2013, 07:36 AM
as far as I understand it on these M11X V-engines, crankshaft gear = engine out .
Title: Re: 450 - M117 Timing Chain Replacement
Post by: Gerard on 21 June 2013, 04:59 AM
Quote from: lube on 19 June 2013, 07:36 AM
as far as I understand it on these M11X V-engines, crankshaft gear = engine out .

I dont know about this engine out myself (thanks lube) but just for more context (ptashek) I did do a crank seal on the straight six M103 engine with the engine in place.  Its quite a lot of extra work , especially getting the front hub pulley off, then retightening it properly afterwards.  I had to make up a few tools to do that job.   Radiator and lots of parts have to be stripped away too.  And when I was at it, I replaced the sump gasket.
I'm sure on the V8 it would certainly be no easier, that is if it can be done with the engine in situ at all!  And if its an engine out job, I can see why so many people let it go!
I also did the top end timing gear on a M117 a few years back (I have a few posts here about it) and found it straight forward, especially with the help available here.

G

Title: Re: 450 - M117 Timing Chain Replacement
Post by: TJ 450 on 21 June 2013, 08:52 AM
There wouldn't be any need to replace the crank sprocket, but you "just" need to remove the timing cover, oil pump and chain(s).

Removing the timing cover with heads in-situ is not recommended.

While you're in there, you might as well rebuild the rest of the engine too.  ::) 8)

Seriously though, there would be next to no gain replacing the crank sprocket, unless the engine is being fully rebuilt. As far as aligning it is concerned, the woodruff key does the trick.

Tim
Title: Re: 450 - M117 Timing Chain Replacement
Post by: ptashek on 21 June 2013, 10:46 AM
Thanks Tim. I've asked, since I have the whole set of timing parts and the manual didn't really give me good signal on how big a job this would actually be. I guess I'll stick to the easy bit for now :) It's my first thing to do after all of steering and suspension gets done.
Title: Re: 450 - M117 Timing Chain Replacement
Post by: djenka018 on 07 August 2015, 05:38 AM
Can anyone please suggest if 1 man can do this without removing the cam followers (or am I better of making/buying the spring compressor)?

I sort of hit the Morton's Fork: either get this car 100% and registered or sell it and buy a Camry.
The timing chain is at the top of the list for too long.
It appears as a simple enough process for 1 man but I am worried that cam kickback by the valve springs can put me in dire situation...

BTW, excellent resource you made WGB.
I found multiple references to it on the web

Thanks
Title: Re: 450 - M117 Timing Chain Replacement
Post by: TJ 450 on 07 August 2015, 08:47 AM
As long as you're very careful, it won't be a problem. I've done it without removing the rockers until recently. Just make sure the chain doesn't slip. I use two or more large cable ties to tightly hold the chain on the sprocket on both sides of the split. The cable ties need to be cut and replaced as you feed the chain through. Just take your time and eventually both ends will hopefully meet up without a gap.

Admittedly it's an absolute walk in the park without rockers though.

Tim
Title: Re: 450 - M117 Timing Chain Replacement
Post by: djenka018 on 07 August 2015, 09:07 PM
Tnx TJ450, that's good news.

I looked up last night and spring compressors are available on flea bay for ~$160 delivered which is, IMO, silly expensive for what it is but it still may be economically viable (I will have to adjust the valve shims afterwards).

Unfortunately I am not aware of anyone selling this in AUS.

Mercedes M114,115,116,117,130,180 Valve Spring Compressor Repair Tools (http://www.ebay.com.au/itm/400971856452)
Title: Re: 450 - M117 Timing Chain Replacement
Post by: marku on 09 August 2015, 11:16 AM
That's pretty cheap for what they are on sale elsewhere MB quoted me well over £300. You can make your own all you need are two forks to go under the cam either side of the lobe with two feet to go either side of the rocker on the valve spring and a short bar angled to clear the intake manifold etc and weld it all together. Seems to work OK although a couple of things are in the way on some cylinders but for what is almost a one time use its cheap enough to throw away after.
Title: Re: 450 - M117 Timing Chain Replacement
Post by: djenka018 on 10 August 2015, 04:26 AM
Marku,

US$66 for the tool is no-brainer against the manufacture but US$50 delivery kills the joy. There are even more expensive ones.
I think I will buy it in spite the total cost. Still less cost then to manufacture it locally.

I never use dealership prices to compare to anything. Their list prices are usually approx 2.5x-4x more expensive