BIGGER W124 diff in a w201 - PeachParts Mercedes-Benz Forum

reinier · #1 12-20-2006, 04:05 PM

Hello,

At the moment, I am busy swapping the diff in my w201 with OM603 engine.
Originally, the car is a w201 2.3-16 with limited slip.

But I drove it today, with the Om603/Getrag manual box, and 3,27 rear end, and the car is to slow, ratio to short.

In 5th gear i wont reach 100 mph without blowing the OM603 because of over-reving.

I have a 2,65 open diff (w124 300TDT, donor for the engine...) next to the car, and want to put it in the w201.

One problem: the rubber flex discs are different, the w124 diff is bigger in all sizes.

What to do?
-is it possible to put the w201 "3-claw" on the w124 diff?? (anyone an online DIY-manual?)
-Go out and search a cardan axle from a w201 with 2.5 (T)D? Is that also larger, just like the w124 thing?

t walgamuth · #2 12-20-2006, 04:39 PM

ouch! i would have bet they were fully interchangable.

but you still may be fine if you swap the three claw. that seems likely to be possible, but i don't know from experience.

tom w

reinier · #3 12-20-2006, 04:41 PM

That looked to me also the best option Tom, but I am a bit afraid of loosening the 3-claw nut, and change the 3-claw.

isnt it so, that by torqing the 3-claw NUT, you have to give the pinion-bearings the right amount of play?

mbdoc · #4 12-21-2006, 08:55 AM

The later 190E 2.6's had a 2.88/1 differential & is a direct replacement for the 16V differential.

2phast · #5 12-21-2006, 11:19 AM

In either 91 or 92, the differential mounts for the axels changed, so if you were to use a later model for the 16 valve, you would also need new axels. I ran into this problem installing a 3.27:1 16 valve diff into my 1992 2.6.

reinier · #6 12-21-2006, 11:51 AM

Thanks for thinking with me!
Mauri from Finnland told me I can transfer the w201 3-claw and rear plate to the w124 differential, and then I am done.

Only thing is to NOT overtighten the nut, because then the bearings of the piniole would be to tight.

Just went to the MBparts shop, and bought all 3 oil gaskets, and a new nut:
16 euro's alltogether

Cant make 'm myself for that kind of money!

Let you know when I am done.

t walgamuth · #7 12-21-2006, 04:04 PM

good.

i suspected that would work.

there is a lot of interchange between different models of mercedes.

tom w

reinier · #8 12-22-2006, 01:06 PM

So, yesterday I cleaned the w124 diff, and put in new oil gaskets. before i loosened the nut of the 3-claw I measured the torque needed to spin the pinion axle. Then loosened the nut, put in the new gasket, and put on the smaller 3-claw from the w201. Tightened the nut until I had about the same amount of torque to spin the pinion.
Tightening the nut wasnt very hard, you dont need a lot of torque. Not more than needed to torque a wheelbolt for instance.

Side gaskets was easy replacing, and then put on the cover of the w201.

Just fitted the diff, in the car, everything ok!

Only problem: the ABS sensor of the w201 can be fitted in the w124 diff, but the hole for the 6mm allen bolt is slightly in another position, maybe 3 mm off.

Gonna use the w124 ABS sensor, and attach the 2 wires to the original ABS sensor.

One note concerning the Limited slip diff of the w201 2.3-16:
The limited slip doesnt have a 'block' with springs in it, to push the friction plates to the outside.

I recently put new springs in a diff. of a ricer, a toyota corolla RWD 1983 or 1984 car, and this diff had such a block with springs in it.

To me, it seems that the 2.3-16 diff is a bit 'old school'/old fashioned, but i dont know an awful lot about limited slip diffs.
For example: the limited slip of a w116 6,9 is of the same limitslip-principle, and that is a 70's car...

The MB diffs just have a couple of friction plates between the satelites and the outside of the diff.

And yes, I am sure this diff was an original 2.3-16 diff.!

t walgamuth · #9 12-22-2006, 01:18 PM

i dont know a lot about them either but it doesnt surprise that it might be a bit old fashoned.

mb is big on if it ain't broke don't fix it!

tom w

ke6dcj · #10 02-08-2007, 09:46 PM

So what's the outcome ?

:-) neil

reinier · #11 02-09-2007, 07:32 AM

Quote:

Originally Posted by ke6dcj

So what's the outcome ?

:-) neil

I have done about 2000 km's with the car now, and everything is fine, diif doesn't whine, or anything.

Only thing: although the previous, original for a 2.3-16 limited slipdiff was a bit worn I suppose (200.000 km on the car), I miss a limited slip now.

When I am throwing the car around very hard, rally style, a bit shorter corners, the inner wheel spins. Also drifting the car is a bit more difficult.

So, first some other small points to fix, and then, in the future, I'll put in the LS carrier from the 2.3-16 diff. with maybe some new friction plates.

gsxr · #12 03-27-2007, 06:28 PM

You can't use the carrier from a 190E-16 because the carrier for the 3.27 gears is different than the carrier for the 2.65 diff. The pinion gear is different diameter so the carriers are a different thickness, adjusting the placement of the ring gear. In a nutshell, you will need to get an ASD diff from a 124.128 diesel, rebuild it with new clutch packs, and swap the output flanges. The input flange should be the same (90mm diameter) as your 201. I'm in the middle of this project myself.

More details here:
http://***************/forum/showthread.php?t=205

Some photos of my LSD project are here:
http://www.w124performance.com/images/W124_diffs/185mm/

I'm hoping to have it back on the road by the end of May at the latest, hopefully sooner. It was NOT a fun project... but it wil be 10x easier next time. (I need to replace the clutches in my 1993 ASD diff... that will be NEXT winter's project.)

Glen · #13 03-29-2007, 02:39 PM

Dave,
So, re: your project...you did NOT remove the pinion correct? Just the ring carrier? And you replaced all the clutches, correct? What % lockup are you anticipating and how did you determine how many and what thickness the clutches needed to be to attain this?

gsxr · #14 03-30-2007, 12:12 PM

Quote:

Originally Posted by Glen

Dave,
So, re: your project...you did NOT remove the pinion correct? Just the ring carrier? And you replaced all the clutches, correct? What % lockup are you anticipating and how did you determine how many and what thickness the clutches needed to be to attain this?

1) Correct - the pinion was untouched, although I did have to swap flanges since the donor diff had a 90mm input and my car needed a 100mm flange to match my driveshaft. Pinion removal is NOT a DIY project. Even the flange swap is not DIY without the special tool shown in my photos.

2) Yes, I replaced all the clutches. They were all worn, that's why the diff was 99% open.

3a) I'm hoping to acheive the factory specs, which would be approx 35% lockup. The FSM only specifies a rotational torque of 80-160Nm, which doesn't correspond to any percentage that I know of.

3b) The Mercedes LSD design is, IMO, poor. You can't adjust for more or less lockup. It's basically a right/wrong setup. You can't adjust the number of shims, only the thickness of the end shim. Too thin and there's not enough lock (or none at all), resulting in <80Nm frictional torque. Too thick (which would increase lock) and you literally cannot re-assemble the diff. I was able to re-assemble mine with 3.1mm shims, but with 3.2mm the small side gears would not rotate into place without damaging the plastic spherical washers. With 3.0mm, it was too loose. Tolerances are THAT close. It's crazy.

4) When the clutches wear, there's nothing to take up the slack (unless you have the full ASD setup, which will compensate with hydraulic pressure). Better LSD desigs use spring packs to provide tensions against the clutches. Looking at the MB setup, I can't imagine it would provide any kind of lockup past about 50kmi. I suspect if you want continued LSD function, you'd end up rebuilding the stupid thing very frequently. I'll see how many miles I get out of mine.

I'm still working on it, but some other things came up... a wind storm the other day tore a roof vent off my shop, so I have to kill half a day replacing it so I won't get rain into the hole in my roof! D'oh. The LSD I'm building is for my diesel. I'm having my dealer friend build the 210mm for the E500, since that requires a carrier swap and backlash adjustment, which I can't do. (He's done a lot of diffs and has the knowledge and the tools.)

Glen · #15 03-30-2007, 03:14 PM

Thanks. I didn't see the tool you mention...I'll look through the pictures again.

Did you have to use a new crush washer when you swapped flanges?

Another question...is the humming noise that some differentials make solely from the pinion-to-ring gear engagement? ie. too much or too little gear mesh?