The W201 differential refresh thread - PeachParts Mercedes-Benz Forum

Stretch · #1 09-28-2013, 04:15 PM

G'day Folks,

"Before you start working on your own differential please consider the comments made in post# 87 http://www.peachparts.com/shopforum/3501569-post87.html"

Here's one for all you W201 owners with noisy differentials. I haven't driven many miles in my W201 at motorway speeds but the few I have done were enough. It is really irritating listening to that over run whine. It is even worse listening to it on acceleration too.

I bought this 3.46 final drive ratio differential for about 90 euros delivered to do up and hopefully end up with a quiet one.

I'm not sure I got a great buy – the input shaft was a bit rough and it turns out there's a knackered bearing race. I was sold this differential as “a quiet one” - it might well have been quiet but it looks like it has been filled with engine oil rather than hypoid gear oil.

So folks here's probably the dirtiest differential in town =>

To help me fix it up I'm following the FSM (http://www.startekinfo.com/StarTek/outside/11832/Resources/201Create/PDF/10005.pdf), but as it is full of special tools that not even the dealer has; I'm going to see how far I can go with as many simple tools as possible.

After getting as much muck off the differential as possible and then draining some of the Castrol GTX that would come out of the drain plug I removed the rear cover and watched the rest of the gunk flop out onto the work bench...

Next trouble that everyone seems to struggle with is removal of those pesky C clips that hold the axial shafts in place. At least on a W201 you don't need to tackle these buggers when changing axles but you do need to take them out for this. The W123 differential C clips are actually a bit easier than these ones because a pair of bent long nosed pliers will do the job. I had to go scrabbling about in my tool box for a thin Allen key – mounted in a pair of mole grips you can yank the C clips out and then chase after them as they try to leave the confines of your garden / garage.

Stretch · #2 09-28-2013, 04:20 PM

With the C clips out the axial shafts can be removed. With these out of the way the axial seals can be taken out.

The differential gearset can be twisted around inside the casing and pulled free – despite what the FSM says about special rigs and stretching the casing this far...

...but not too far...

To remove the nut on the input shaft you need to break the peening and then get a deep 12 point 27 mm socket. I don't have a deep 12 point 27mm yet so I drilled and chiseled like a good 'un. I partly did it to just get on with the job and not waste time waiting for internet deliveries and partly because when turning the input shaft it was obvious something was wrong. I got that nut off in the end and then used a three legged puller to pull off the yoke.

The FSM reckons you need a special rig and a puller to push the input shaft into the casing. You could use a hammer and just knock the shaft into the casing – but if you do make sure you don't mushroom the end of the shaft. Use a bit of hard wood to protect it.

Using wood to protect both the case and the shaft I used my hydraulic press.

Stretch · #3 09-28-2013, 04:23 PM

To reach the first of two tapered roller bearings on the input shaft you need to remove the seal. Mine was stuck – seal removal tool couldn't budge it. Simple solution is to deform the seal with a chisel – gently does it

Once the seal is out you need to jump on your push bike off to the local motor factors and buy as big set of circlip pliers to get the tractor sized circlips out

Here's the bearing

Here's a damaged bearing race that I'll have to replace.

Stretch · #4 09-28-2013, 04:24 PM

Well that's as far as I've got so far

There's not much in 'em (when you get the motor oil out)

If anyone's got some tips and tricks I like to hear them.

vstech · #5 09-29-2013, 06:45 AM

interesting.
I was discussing this very project with Whunter today...

Jaybob's 300TD had a growl... his diff gears are POLISHED, the spiders are pitted and covered with nasty bits... I have two spare diffs for 124's so I'm considering which is the better choice, but each has it's problems... the first choice, (since it's sitting on my shop floor) is one from a 95TE that rolled a chain link fence around the yoke/driveshaft... tons of wire tight against the case, jammed around the yoke, and destroyed the pinion seal... so, it's all gotta come apart to fix it. and I HATE dealing with the pinion crush/preload.
the other is still in the parts car, and it's got over 310K on the clock...

vstech · #6 09-29-2013, 06:48 AM

first thing I noticed is the axle stubs are HUGE on that differential... the 124's are only slightly larger than the bolt ring...

Stretch · #7 09-29-2013, 08:05 AM

Quote:

Originally Posted by vstech

first thing I noticed is the axle stubs are HUGE on that differential... the 124's are only slightly larger than the bolt ring...

I thought that too - they cause an obstruction with the drain plug

(Can of course be got around but then you need a conventional Allen key and all of the pipe slipping off of it swearing and injury related stress!)

vstech · #8 09-29-2013, 08:12 AM

is it an euro thing? or a manual thing? or a 201 thing? are both your diffs the same?

Stretch · #9 09-29-2013, 08:25 AM

Both of my differentials are 3.46 with ABS - fitted to my gasser ( <= don't tell the moderators I'm posting in DD as usual!) W201.018 - this could be a post 199X thang???? W201 upgrade thang? Mine's a 1992.

layback40 · #10 09-29-2013, 08:30 AM

Need pics of the teeth on the crown wheel & pinion to see the ware marks. That will show if its going to be quiet when you put it back together.
VS , I would go for the diff with the chain wire. I have replaced several pinion seals on diffs when fence wire twisted around the yoke & destroyed the seal. Just did the pinion nut up 1/8 turn further than it was before I undid it. Have done it most recently on on 123 & on a Dana 35. Both have crush washers I didnt replace.

vstech · #11 09-29-2013, 08:43 AM

Hmm... yeah, but you're upside down... gravity works differently down under don't it?

vstech · #12 09-29-2013, 08:44 AM

if it was my car, I'd try that, but for a customer especially one that's a valued Diesel Discussion member... I don't think I'm willing to cut corners on a differential...

layback40 · #13 09-29-2013, 08:51 AM

Quote:

Originally Posted by vstech

Hmm... yeah, but you're upside down... gravity works differently down under don't it?

Yes but I was upside down when I was working on it so doesnt that make it right side up for your part of the world?
I agree that working on some ones car is different than your own. I would still go for the diff with less miles. Best have a very good look at the mating surfaces of the teeth. Spider gears tend to ware badly also. Setting up a diff is a real art, especially if the ware on the crown wheel is uneven.

Stretch · #14 09-29-2013, 11:09 AM

Quote:

Originally Posted by layback40

Need pics of the teeth on the crown wheel & pinion to see the ware marks. That will show if its going to be quiet when you put it back together.
...

Here are the wear marks.

The oil in the differential was so dirty it seems to have stained everything a dull yellowy colour.

I get the feeling that the shiny parts on the teeth are non contact parts - but may be I'm over thinking this...

What do you think?

w123fanman · #15 09-29-2013, 03:27 PM

so as a general question related to the topic, I'm planning on switching the entire ABS from my parts car (93-190E 2.6) over to my car (87-190D) and was just wondering if the ABS sensor port is on the regular diff or did Mercedes make the housing different? I could switch out the diffs but the 2.6 diff is 3.07 instead of 2.65 as in the 190D 2.5 and I'm not sure if I want to mess with that.