300TDI rear main seal leak?

glester

Well-known member
Jul 11, 2017
96
3
Seattle
So...I just finished replacing the crank on my 300TDI and also swapping the auto for a 5-speed (R380). https://discoweb.org/showthread.php?t=96637

After driving it around I noticed that oil seems to be leaking right out of the wading plug hole at the bottom of the bell housing. It seems likely that it's the rear main seal or a t-seal.

You think it would be easier to pull out the radiator/intercooler and pull the engine forward with a crane or pull the transmission back and drop it out?

Also, I've been reading a bit on how the rear main seal can be a bit sensitive. It was a new one and put on using the plastic ring that helps get it onto the crank. Anyway, any advice here would be welcome.
 

jymmiejamz

Well-known member
Dec 5, 2004
6,008
361
35
Los Angeles, Ca
I hate pulling transmissions, so I would pull the motor out to do it. I would only consider pulling the transmission if I was doing the work on a lift.
 
In standard 300TDI is used to move engine forward, only loosing viscous fan, in order to get the few centimeters to change clutch.
All hoses are prepaired to.
But in order to loose flywheel screws you must unscrew both engine supports from block sides, let engine down a little.
Rear main seal is not a perfect thing, you see.
Some replace these rubber inserts above with RTV silicone sealer like Loctite 590 black.
And Crankshaft surface in seal working area must be perfect
Some use to modify this seal adding the 2,8 seal that includes two more screws in the bottom.

Regards
 

glester

Well-known member
Jul 11, 2017
96
3
Seattle
Gave it more time and still was leaking. Pulled the engine out again this week and it was leaking from the base of the rear main seal. Maybe a bad gasket. Anyway, I pulled off the rear main seal, used Right Stuff as a gasket and put it back on. So far it's all good. There were some other small leaks that we're more clear after pulling the engine out. Small leak from the cyclonic breather and from the return on the turbo. Took care of those as well.