I'll try and remember to use one of the ones from England next time that have both inches and centimeters on it for you next time - prepare to be cross eyed.

Well the home made spreader thing kind of works
 

The plan was to use this thing

http://www.peachparts.com/shopforum/...-spreader3.jpg

And combine it with a vernier caliper to measure the deflection applied like this

http://www.peachparts.com/shopforum/...1&d=1396187705

The problem I have with this idea is that the jaws on my caliper are not deep enough to go round the crown wheel when it is fitted. I could go and buy a deep jawed caliper for about 80 euros but...

...well...

...I'm tight.

So the plan now is to use the spreader very carefully!


For example, I've been hunting about for yet more of the circlip shims so I decided to canibalise the original differential. So far I've been able to remove the circlips from their holes in the differential casing without expanding / stretching / spreading the casing. This time however they weren't going to give up easily.

So I fitted the spreader and applied a force until the circlip would just move and come out.

I took great care not to over cook it. The best I can do in the situation (other than buying more stuff).

http://www.peachparts.com/shopforum/...1&d=1396187768

{Note to self - LHS was 3.75 RHS was 3.67 => probably 3.65?}

A little bit of CSI on the original differential
 

As I've been canibalising the original differential for spares I thought I'd have a quick look at the condition of the parts to see if I could figure out why it was making a whining noise.

The crown wheel and pinion teeth look OK

The axial bearing cups show signs of over heating - a bit of blue staining. They have a fair amount of very light pitting but that is quite common (some might say normal!).

I've measured the pinion shaft friction and it is within specifications. I measured 85Ncm and the range for worn bearings is between 50 and 100 Ncm - so not bad.

The pinion shaft is, however, quite notchy when you turn it.

I plan to remove the pinion shaft nut and remove the shaft tomorrow when I can try out my new pneumatic impact gun.

=> Note to neighbours - you have a very considerate mad mechanic living in your neighbourhood who elected not to fire up the compressor on a Sunday afternoon - you don't know how lucky you are! <=

It's 9:20 a.m. on a Sunday morning, and I'm just getting ready to fire up the lawn mower.

Does that make me a bad neighbor? :D

Where I live there are a lot of retired complaining old gits who really need to get on with their own lives - I've lived in other places when it is entirely normal to be busy on a Sunday - I've heard that it is actually illegal in Switzerland and Germany to cut grass on a Sunday (I'm not sure if that's true though).

A little bit more CSI on the differential that was originally fitted to the car
 

Today I played with my new pneumatic impact gun - whipped the pinion nut off nice and easy.

Before I got to that stage, however, I decided to clean up the differential and make some contact patch imprints in engineers blue.

To do this the crown wheel needs to be removed and cleaned with degreaser / brake cleaner. Same needs to be done to the pinion wheel.

I then re-assembled the differential:- crown wheel back in and refitted the axial shims. I painted part of the crown wheel with engineers blue and then ran the muck past the pinion wheel in one direction and then wound it back so I could see it.

The process of doing this is shown in this youtube video

Differential Ring and Pinion Gear Setup - YouTube

Take your time to listen and watch this video - it is very slow and boring but it does have lots of good information in there.

There is also a link in the video description to this handy PDF

http://departments.weber.edu/automotive/YouTube/Weber_Ring_Gear_Contact_Pattern_Interpretation.pdf

This shows you how to interpret the wear patterns you see.

Here are my wear patterns on the original differential - this is not the "new" one I've been working on up until now.

Crown wheel fitted to differential casing

http://www.peachparts.com/shopforum/...1&d=1396269724

http://www.peachparts.com/shopforum/...1&d=1396269936

It might be best to remove the crown wheel from the differential casing if you are having trouble seeing

http://www.peachparts.com/shopforum/...1&d=1396269936

http://www.peachparts.com/shopforum/...1&d=1396269936

From the patterns above you can see on the concave side of the gear surface the pattern is mainly towards the outer side or heel part of the cog.

On the convex side it isn't so clear in the pictures but the contact patter is slightly more towards the inner side or the toe part of the cog.

Looking in the handy PDF on the weber automotive site you can see that this means the pinion needs to be closer to the crown wheel.

This can also be seen in the following picture...

http://www.peachparts.com/shopforum/...1&d=1396269936

...where there isn't much blue at the end of the pinion wheel closest to the bearing and casing.

A little bit more CSI on the differential that was originally fitted to the car (2)
 

After whipping off the pinion nut I pressed the pinion out of the casing and found a whole load of swarf

http://www.peachparts.com/shopforum/...1&d=1396270546

The condition of the bearings isn't great - discoloured - signs of over heating - signs of uneven wear - signs of water / moisture ingress / rust

I've come to the conclusion that the reason why this differential was whining was mainly due to a distinct lack of oil changes during its 100,000 mile life span.

It seems to me that the pinion shaft bearings have suffered and worn at a greater rate than the axial bearings.

I think - only think(!) - that I've done the right thing removing this differential from service. A different oil might have quietened it down but there's little way an oil change in a differential is going to remove the swarf near to the pinion shaft bearings. These bearings would have continued to fail.

Moving forward
 

Here's a reminder. After some fiddling about I've got a nice central contact patch on the drive and coast side of the gear teeth on the crown wheel.

The following shims fit into the casing with out stretching - but there is no noticeable axial play. Please note this is not applying the correct pre-load to the axial bearings but it gives the position that the crown wheel needs to be =>

http://www.peachparts.com/shopforum/...1&d=1396464975

http://www.peachparts.com/shopforum/...1&d=1396464975

I got some more shims from the dealer today for the axial bearings.

I have now fitted slightly thicker shims than those shown in the pictures above to get the correct pre-load by stretching the case (very carefully because I can't measure the stretch). I ended up adding 0.1mm to the left hand side and 0.05mm to the right hand side.

I've run out of daylight now so I'll check the contact patch tomorrow and finish up the last few bits

Gasket remover has been applied to the case cover

http://www.peachparts.com/shopforum/...1&d=1396464975

Differential vent was all clogged up - got a clean and a coat of paint

http://www.peachparts.com/shopforum/...1&d=1396624541

Finishing off
 

I can't believe I've not taken a picture of measuring the backlash!

That is really irritating. Too late now it is all back together again.

Anyway I spent a bit more time checking the teeth meshing of the pinion and crown wheel and reached the conclusion that the pinion might need to be slightly closer to the crown wheel. This is a pain in the arse as the pinion seal needs to be destroyed to get the pinion and the larger bearing cup out of the casing so that a slightly thicker shim can be fitted. You then need a new crush washer on the pinion shaft etc

I'm telling myself it is a bit borderline - I think it is worth giving the differential a go as it is. I'm guessing and hoping it is close enough. If I get any whining noises from the differential once I've fitted it I at least know what I need to do!

So after checking the backlash for the final time

[Sorry no picture]

I zoomed ahead and fitted the axial seals

http://www.peachparts.com/shopforum/...1&d=1396625321

http://www.peachparts.com/shopforum/...1&d=1396625340

I used a bit of wood to ease them into place. There is a special tool for this that of course I don't have and the FSM says to use a bit of oil to help them go in. At chez Stretch it was hammer time.

I moved too soon and forgot about the 1.5mm spacers that need to sit on top of the differential cage inside the axial bearings

http://www.peachparts.com/shopforum/...1&d=1396625472

Luckily they do slip easily through the axial seals

http://www.peachparts.com/shopforum/...1&d=1396625569

No stress - no disaster!

http://www.peachparts.com/shopforum/...1&d=1396625508

Make sure the spacers fit snugly in their little recesses

Fitting the axle flanges
 

Now the axial seals are in place you can fit the axle flanges. Make sure they go in and out of the side cogs smoothly before you fit the circlips.

The circlips need to fit really snugly.

Tapping the circlips in place with a bit of wood is a good start...

http://www.peachparts.com/shopforum/...1&d=1396626220

...before finishing them off with a narrower punch

http://www.peachparts.com/shopforum/...1&d=1396626314

Tap the eye in the circlip round so that it is positioned near to a land in the differential side cog to make it easier if you need to remove the circlip again.

http://www.peachparts.com/shopforum/...1&d=1396626322

Try to wobble the axle flange (black arrow) to see if you can see any movement in the side cog (red arrow).

http://www.peachparts.com/shopforum/...1&d=1396626473

If the side cogs wobble the circlip is not snug enough

Remove the circlip - measure it and find a thicker one until there is no visible wobble and you couldn't fit a thicker circlip.

http://www.peachparts.com/shopforum/...1&d=1396626533

Finishing up
 

Last chance to clean out all of that engineers blue (isn't really really a big deal if there's some left in there)

http://www.peachparts.com/shopforum/...1&d=1396626821

RTV for the back cover

http://www.peachparts.com/shopforum/...1&d=1396626821

I found some super posh lazy arsed push a lever instead of squeezing a tube stuff in the cellar that had a rather large nozzle hole. So I scraped the goo about around the bolt holes to get it as even as I could. I don't want to end up with great big gobbules of RTV on the inside of the case

http://www.peachparts.com/shopforum/...1&d=1396626821

I nipped up the bolts by hand to allow the RTV to set before the final torque down

http://www.peachparts.com/shopforum/...1&d=1396626821

And that ladies and gentlemen is it!

I hope it is bloody quiet - Rolls Royce / Maybach quiet after all this bloody shim palaver I've gone through!

http://www.peachparts.com/shopforum/...1&d=1396627084

Looks good as new. Well done.

Im bringing a question here to add to the 190e diff. Q&A ,What is a good candidate for a 2.3 16v replacement rearend Stretch ?,the limited slip rearend on these cossies are really scarce ,Im curious if the parts to rebuild these type of diff. are still available .You have really captured some great details in this writeup.I currently have flex disc issues ,so bad infact that the drive shaft was banging ,Ill be bringing the driveshaft off and during my first inspection the rear yolk has a 1/8th slack of rotation.Should I just continue using it with some good diff. fluid ?

I don't want to present myself as some sort of authority on what's good and what isn't - you have to take my experience in context. I'm just some stubborn chap who has taken pictures written a bit of text and done his best not to buy special tools.

I've only done this to one W201 differential - and that's a bog standard one - no fancy limited slip friction clutches behind the side gears in the differential.

I have read the manual for the setting up of these side gears with the extra limited slip clutches though - it looks like a very simple system. I didn't realise until very recently that that's how Mercedes "made" limited slip differentials. I got that information from greazer's sleeper thread =>

http://www.peachparts.com/shopforum/diesel-discussion/333744-sleeper-part-deux-14.html

From my limited understanding of limited slip diffs I think the Mercedes version is a poor man's approach to doing the job. Those Quaife jobbers are much nicer =>

http://www.peachparts.com/shopforum/diesel-discussion/337976-fancy-some-lsd-your-diesel.html

I don't know about the parts availability for the LSD versions - if you look on the Russian EPC (available via EverythingBenz - Mercedes-Benz Forum and Web Search Using Google) there are quite a lot of part numbers that do not correspond with the parts I bought for my differential

Êàòàëîã MERCEDES

According to the data on that site the rear end ratios for the US of A were 3.27 whilst in Europe we got a 3.07

If you swap the differential for a different version making sure of the same rear end ratio will help you not having to recalibrate your speedo

Banging might also come from the universal joint on the propshaft. When you come to do your flex discs rotate the UJ joint and feel for any notchiness

I dunno - may be you can do that - the fluid needs to be special for a limited slip differential I guess that comes with a premium price tag.

The problem with asking me something like this is that you all know what I'm like - it says it in my signature - I will take it to bits.

I'd be checking the back lash and applying engineers blue - I'd be looking for trouble - any excuse to have the thing in bits - I have been told on many occasions that most people like to drive their cars - horses for courses I guess (but I don't really know what's wrong with you all!)

My puzzle skills are lacking but with the tortural technical teachings of your photo phindings are phantastic puzzle placers.