Leaking Rear Main Seal
 

Hello out there!
I have a 1990 420 SEL with a leaky rear main seal. The mechanic who looked at it estimated the repair at 8 hours. Is this a good estimate for shop time charge?

Thanks

Dealer shows 8.6 hours

God Bless
John

It's standard practice to replace the rear cover on the engine that the seal mounts in also.Also be sure they replace the bolts holding the flex plate/flywheel to the crankshaft. The bolts are stretch bolts good for one use only. Depending on how many miles and how bad the crankshaft is grooved from the seal they may need to install a repair size seal also.

Robert

It would probably be best to just install the repair seal. I had the front main done on my M104 and the regular seal did not fix the leak so we had to go with a repair seal.Which just moves the sealing surface a few millimeters back

Rear Seal
 

Yea, mine leaks too but not gushing. Was told to live with it due to the cost to repair. 1989 300E with 110,000 miles.

Lots of the effort is R&R the transmission. I don't think a rear crank seal falls into the same enviroment with wear as the front seals.

I'd see if for a few extra hours- they'd do the pump seals, and front clutch pack(behind the pump). Seems like low hanging fruit and those are the first areas of failure on these MB tranmissions.

Be sure to change the torque converter seal and service the transmission while you're in there.