News:

The Org - Serving W116 Enthusiasts since 2004!

Main Menu

450 - M117 Timing Chain Replacement

Started by WGB, 20 April 2007, 10:15 AM

oscar

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.
1973 350SE, my first & fave

116.025

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?

oscar

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.
1973 350SE, my first & fave

Tomi

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

koan


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
Boogity, Boogity, Boogity, Amen!

WGB

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 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

SELfor50

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.

WGB

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


lube

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 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.

WGB

#25
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

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



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



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



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

Big_Richard

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.

lube

#27
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.

WGB

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

TJ 450

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
1976 450SEL 6.9 1432
1969 300SEL 6.3 1394
2003 ML500