PeachParts Mercedes-Benz Forum - M104 rear main seal replacement advice pls

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M104 rear main seal replacement advice pls

I did a search and found that the oil pooling in my belhousing probably indicates a rear main seal leak. Any advice on the r&r procedure would be greatly appreciated.

Is there a definitive test for the rear main seal? I am certain it is oil (not trans fluid) and it leaks about a quart per thousand miles.

TIA,
Tom

All you have to do is get the transmission out of the way. Plan on replacing the front seal in the tranny while it is out.

Have you reduced the oil charge from 7.5L to 7.0L? There was a notification from MB about this change. This would be about halfway between min and max on the dipstick. The higher level was too tough on the main seals.

Re: M104 rear main seal replacement advice pls

Quote:

Originally posted by aTOMic
I did a search and found that the oil pooling in my belhousing probably indicates a rear main seal leak. Any advice on the r&r procedure would be greatly appreciated.

Is there a definitive test for the rear main seal? I am certain it is oil (not trans fluid) and it leaks about a quart per thousand miles.

TIA,
Tom

Please make sure the head gaskit is not leaking down the right rear corner to the bellhousing...looking like a rear main seal
Use the Mercedes Sitehttp://www.startekinfo.com/StarTek/
It Will take you step by step..Its Easy!Done Lots of them!
I Would recommend to replace the Rear Main Seal cover
when you replace the rear main seal..PLEASE be very careful NOT to damage the oil pan gaskit ...when doing the job!
When you remove the trans ..I would reseal the trans filler tube(DIPSTICK) and replace the flex disc..

On The Trans Its a Very good time to reseal the front pump on the trans...But Unless You are good with Transmission repairs
I Would Not do this yourself....

Quote:

I Would recommend to replace the Rear Main Seal cover
when you replace the rear main seal..PLEASE be very careful NOT to damage the oil pan gaskit ...when doing the job!
When you remove the trans ..I would reseal the trans filler tube(DIPSTICK) and replace the flex disc..

On The Trans Its a Very good time to reseal the front pump on the trans...But Unless You are good with Transmission repairs
I Would Not do this yourself....

Should I have a spare oil pan gasket on hand in case I damage the old one?? How hard is the oil pan gasket while I'm at the RMS?

Anyy further help would be appreciated,
Tom
P.S I will look at the startek site but I am compiling a list of things I want to look up while I have access to it (It's pay-per view for those who didn't know).

Quote:

Originally posted by Kestas
Have you reduced the oil charge from 7.5L to 7.0L? There was a notification from MB about this change. This would be about halfway between min and max on the dipstick. The higher level was too tough on the main seals.

Absolutely correct..
Mercedes Service B. - 00-134, Ref 18/45
They also recommend refraining from topping off beyond 1/2 mark when warm/level after 2 min wait/check between oil changes.
Not to say you do not need a seal, but rather to address this TSB before-hand.. I have seen this remedy others of the same complaint.