W116.org

I am now preparing for front seal replacement.




However, I'm faced with the problem of how to lock the flywheel or counterholding the crankshaft whilst applying the enormous torque required to undo that crankshaft nut. 
Ideally, the starter flange detent would be a nice addition to my tool kit right now, but is there a safe alternative?

Tim

How about the Rope method ?

The detent device is definitly the safest way to do it though, It may be worth enquiring what the tool is worth at the stealer ship, it has an MB part number.

I'm not keen on the idea of the rope trick - bit risky.  When I did the front seal on my 280SE, I locked the flywheel in the area exposed by the bell housing access plate.  The torque on the M110 front nut is 400Nm.  The M100 differs a bit in arrangement, but maybe you can adapt my trick.  On the M110, there are 6 bolt heads passing through the flywheel into the torque converter.  The heads are recessed into openings in the flywheel.  I foud a socket that fitted tightly into one of the recesses - it may have been 16 or 17mm.  Rotate the crank in the forward direction until one of the recesses just appears enough to jam the socket it.  Fit the socket, start applying force to the crank front nut in the release direction, inspect to see if the socket has lodged safely.  THen go for it.  I was concerned that the amount of force I was subjecting the socket to, it might break or crack the alloy bellhousing - but it all went well. 

Never come across the flywheel lock for our engines while browsing the tool websites and never dared ask the price at a dealership.

One of the local independents said he jams bits of wood in between the ring gear and bell housing but I couldn't see that working.

My method was to take a 250 or 300 mm square of 6 mm mild steel and using the crank pulley as a guide mark and drill the six bolt holes, mark the circumference of the big center hole and cut it out using the join up the little holes method and start filing.

Drill a hole at each corner of the square, drill matching holes in a piece of 50 mm angle iron about a meter long so that it mounts along one side of the square.

Bolt the plate to the crank (recall needing some spacer washers because the harmonic damper flange is proud of the crank end), bolt the angle iron to the plate so the end of it sits on the ground to the left looking at the crank end, now start heaving on the bolt with a 50 mm socket and a long, long tommy bar.

EDIT: I found the plate, it's actually octagonal, 200 mm between opposite faces, with eight bolt holes for angle iron, one in the center of each face.

koan

I would like to retract my suggestion about jamming a socket onto one of the bolts from the flywheel to the torque converter - I've just spent the evening refitting a 6.9 sump, and while I was under there I examined the arrangement, and I think my original suggestion would be a very very bad idea on the M100. 

This IS a M100, and should be treated with respect.  Koan's suggestion is far, far better, and I think it would be well worth the time needed to make up the tool he describes. 

The M100 suitable MB approved starter detent is part number 116 589 01 40 00
The genuine M100 hub puller is 100 589 12 33 00

May be worth checking.

The 6.9 nut is also tightened to 400Nm

I have the genuine Porsche Flywheel lock and will post a photo when I get a chance.

It may be possible to make up a plate that bolts to it to convert it for M-100 use

You are welcome to borrow it if you remember to return it under pain of death (or worse).

I assume you need it real soon but if you can wait a few days I will look at the picture of the M-B one and see if the Porsche one can be modified - or you are welcome to borrow it.

I'm having a shed day and will PM you my mobile if you want to discuss it.

Bill

Here is a picture of my Porsche flywheel lock P233 for front engined porsches.



The distance between bolt hole centres is 105mm

Front to back is 40 mm and inside mounting surface to end of teeth is 30 mm.

It may be possible to mount on one or either starter motor bolt (depending on whether you are loosening or tightening the crankshaft nut) and put a wedge between the housing and the tool to hold the teeth in mesh or if the flywheel teeth are deeper than 30 mm you could bolt a plate to the back of the tool to hold it in the correct mesh.

Bill

Addendum - Measured my starter bolt distance today and the centres appear to be the same 105mm apart. Maybe Porsche and Mercedes Bosch starters share some dimensions. It only depends on depth to the teeth, tooth size and off centre position whether or not it would work as it is.

I know Porsche used a number of Mercedes bits at times - maybe they used the same or similar in starter motors.

let it be known that the honourable Dr Babe, called me as he didnt have tims number to let tim know he had this device! 
didnt get the missed call till on the way home though Bill, but im sure Tim would have been very grateful...he had success regardless! 

Anyway the offer is still there if you want to try it out.

I changed the engine mounts and transmission mount on my 6.9 today and was gobsmacked  when I realised the bolt holes were the same. I wasn't going to take out my starter just to see if it fitted and was getting a bit tired when I spotted the cover plate on the right hand side for the alternate starter position used in LHD but I might remove this cover plate sometime and see if it works if someone doesn't try it out sooner.

Anyway if you want to buy one yourself they are only US$44.95 and are available here

www.944online.com

This place offers the same level of service as AutohausAZ except that they use Credit cards rather than Paypal and need a copy of your card and your drivers licence faxed to them with the first purchase. I used them repeatedly when my Porsche was alive.

Bill

Thanks for all the assistance, guys. 

Well, with a bit of team work, we had success using the "Rope Method". When it comes to torquing the nut back up, I think Bill's Porsche flywheel lock will be the preference.




I purchased a puller, but it only came with two bolts the correct size and I don't want to ruin the flange, so the harmonic balancer remains installed at the moment. I will investigate how I will remove it over the next week or so and will hopefully remove it next weekend.
In fact, I'm going to need to lock the flywheel when using the puller, so perhaps I'll call you next Saturday, Bill.

Tim

If bills device fits in the hole correctly.... - please order me one too, It'd be great for future work.

I'll be getting one too.

koan

I purchased a "heavy duty" harmonic balancer puller today and subsequently removed the balancer with the aid of Dr. Babe's Porsche flywheel lock. I highly recommend this device!
The seal itself was due for replacement, but wasn't too bad. However, the crusty sludge on the oil pump chain doesn't look that great.





...Tim

Good job, that's a very nice puller, it looks more substantial than the usual cast Y shape type, where did you find it?

What  about WGB's Porsche flywheel lock, did that fit without modification?

Are you aware of the manual (as in book) recommended way of getting the hub back on? Heating to 80C in an oven and sliding it back on in one operation.

koan