1997 E320, flex disc and rear trans seal leaking
 

I own a 1997 E320, with 190,000 miles on it.....On the way home today, I heard a thumping sound under the car, and having owned many Mercedes in the past, assumed that my flex disc must be on its way out.....

I jacked up the car and looked at the front flex disc and saw that it was clearly deteriorating, as it looked like a Chia pet!!!

What I also noticed, and it somewhat disturbed me, is that it appears as though my transmissions rear main seal is leaking, as well...

Common sense tells me that if the flex dic is causing the driveshaft to "wobble" that it would be pretty difficult for the seal to do its job....

My question is: "Should I replace the rear main seal when I replace the flex disc, OR should I assume that the seal has not been damaged and will continue to work once the driveshaft no longer wobbles as the the newly installed flex disc will restore the driveshaft's steadiness????

Also, worse case secnario, is it very difficult to access the rear transmission seal and is it difficult to replace?????.....I have changed front main transmission seals on W123 Mercedes diesels so I am competent at changing seals.......Just want to know if there's something odd that I should look out for on a 1997 E320's rear transmission seal replacement proceudure????

Thanx to ALL in advance, as always any input is more than greatly appreciated!!

Big Dee!

99% of the time that rear seal replacement is easy, as long as you have the correct socket. Removal of the output flange can require a puller that other 1% of the time.

Yes, you would be smart to replace that seal.

Thanx. M.B. Doc!!....

BAD NEWS!!!

I replaced the front flex disc and rear transmisiion seal, I insured that the the flex disc was properly seated and tightened the bolts accordingly....but I noticed that the rear flex disc was starting to look a bit shabby, but figured that I'd replace it next week.

Went for a test run, everything felt great, then SUDDENLY I hear the new disc breaking apart and there was smoke is billowing from under the car.....The smoke was from my rear trans seal (just installed PROPERLY, as I was an ASE Certified tech for over 15 years in my younger days) leaking again........I nursed the car home and there it sits.

What did I miss???....I've owned MANY Mercedes Benz automobiles throughout my life and have changed flex discs quite a few times.....But this has NEVER happened before!!!

Can someone tell me what to look for????? What could have caused my newly installed flex disc to fail so quickly????

Thank you all so much!!!

CORRECTION!!!!!!

FRONT FLEX DISC WAS NOT DAMAGED!

REAR FLEX DISC APPEARS TO HAVE DETERIORATED RAPIDLY!

What are the chances that the driveshaft center carrier support is defective, as well....I haven't removed the access cover but I pushed on the driveshaft to see if I could feel play in it, I also twisted it back and forth to see if there was a lot of play in the center.......

Since the rear flex disc is obviously defective ( I will be changing it inthe next few days), would it cause the driveshaft to wobble or vibrate enough for my rear transmission seal to leak again, OR is there something else that I should also be looking for in the transmission tailshaft area that may be defective, as well??????

Once again, thanx!!!!!