If one is careful in removing the driveshaft output flange from the rear diff, is it necessary to replace the radial diff seal?

If so, are there any special measurements or tooling needed? I'm not dismantling the diff, just changing the driveshaft output flange. I was thinking with the proper drift, I can re-install the radial diff seal.

However, other than the proper torque, do I need to measure any play, or drag when re-installing the 12-point collar nut?

Thanks in advance,

:-) neil
1988 360TE AMG
1993 500E

You should be able to reuse the seal on the Diff
If You replace the Yoke please make sure that the Yoke is Clean
with NO Scratches / ridges to avoid a leak..Clean it with very fine sand paper..if any scratches...
Also Be VERY careful when Installing the Yoke..NOT to knock off the spring on the seal...If the spring is Knocked off You WILL have a Leak!

The Seal is NOT a big job to replace with the yoke removed!

How do I measure the "friction torque" dry (oil drained)?

The docs specify 125-150 Newton-Centimeters. To convert to
Newton-Meters, do I simply divide that by 100?
If so, that's 1.25-1.50 Nm. Is that correct?

I did find the PDF's on the W124 CD-Rom (testing210.pdf and
tech_mod210.pdf)

Tech_Mod210.pdf (p.5) states to ALWAYS replace the pinion seal.

Moreover, as of 1/4/1998, an improved pinion seal (pn# 025.997.0047) and a improved flange provides better protection from contaminents. It also states that the OLD flange can be used with the improved seal.

Unfortunately, I don't think that is true (old flange w/new seal)
because the "improved" seal now has a "valley/dip" where dirt can accummulate IF used with the old flange. Only a new flange
($188-wholesale) has a longer/wider lip to protect the "valley/dip" from contaminents.


Since I'm swapping flanges, I'm concerned that the swapped flange with the old seal may leak. I'd change the seal in a heartbeat, but I don't want to spend $180+ IF I can trust the old flange can be used with the improved seal. Note: it doesn't leak, but this is swapped flange. . .

:-) neil

Old Seal w/Old Flange:


New Seal w/Old Flange:

Need some help. I know old post but I hope someone can give me some insight. I had the misfortune of my car sliding off the jack and the car landing on the flex coupling and differential yoke. It tore the brand new yoke to shreds. Nothing else seemed damaged so I bought a new one and reassembled.

Well, when I went to dive the car while giving it gas (not when coasting) at speeds over 60mph a horrible vibration that was not there before this incident. I checked everything and one of the ears on differential flange was apparently bent by about 1-2mm (I measured with mm calipers). I suspect that is the source of my vibrations. So I have decided to try and replace the flange. I removed the 12 pt nut but now I cant get the flange off. I broke 2 pullers. Is there a secret or what am I doing wrong. Also am I going to be able to get the new one back on since I did not take into account the original torque that the factory nut had (stupid). Any info much appreciated.

Have you tried putting some heat on the flange with the puller hooked up?

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I am afraid to heat that, I dont want to damage anything like the bearings. I am going to try and get my hands on a 15 ton puller and see if it works.

Any tips on how I can get the new nut to the right torque without damage?

Just block the flange and torque it down.

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