Transmission Rear output shaft lip seal leaking

[wintergreen]

2000 Subaru Legacy L, 5MT, NA, 221,000 miles.

 

 

Originally I bought the car with 183,000 miles 5 years ago. First thing I did was replace the center drive shaft with a new "Wholesale Import Parts" drive shaft. Didn't touch the rear shaft seal at that time.

 

 

Next I change the transmission fluid to Mobil1 synthetic 75W90. I did not have any leaks at this point in time.

 

 

Last year I pulled the motor, so the transmission was at a slight angle while pulling it. After installing the motor with a new clutch there was a fair amount of clutch chatter and drive line vibration taking off from a stop. The rear transmission mount is a little torn and worn. This is when I noticed the rear output shaft leaking gear oil. Once summer came around with warmer temperatures it didn't leak.

 

 

Now this winter I noticed it leaking again. Not much, because level isn't dropping much. Parked after driving I can smell burning trans fluid.

 

 

I installed a Subaru OEM seal and the leak was worse. Took it out and installed an aftermarket (National brand) seal and it is better, but still leaks/drips a little. The slip yoke shaft also looks fine, no wear mark from the seal lip. Gear oil looks good, good color, normal smell.

 

 

 

I'm going to replace the bad rear trans mount to help with the possible extra trans tail movement. Maybe that is part of the problem.

 

 

 

I can't figure out what is causing the leak and I'm frustrated.

 

Time to change the trans fluid?

Does synthetic like to leak?

Is it the cold (only 30°F)?

 

 

What am I missing here?

 

 

Thanks.

[rhino6303]

Pictures? Are you sure it is from the rear seal? It's super common for the shift shaft seal to leak as well.

[wintergreen]

Yes I'm sure it's the yoke seal, fresh fluid from that one dripping right on the cat shield. The shifter shaft has a dry dirty area around it, nothing fresh or new.