I left a post last week about an oil leak. After more investigation this weekend, it appears to coming from the rear main oil seal and leaking down the transmission housing. I called around today and got quotes of around $450 to replace the main oil seal.

I also think I have a small leak from the transmission. While they are pulling the transmission to replace the rear main seal, should I also have them replace the transmission seals ( I think there are three) at the same time? How much more effort is this? Also, should I have them replace the tranmission mount? The car has 160k and the has the original mounts.

Thanks in advance for any advice.

Jeff Breeden

Tell us a little more about your leaks...How many miles on your car?

I'll take the tranny leak first. Where is it leaking from? If it appears to be near the back, then it is probably the talishaft bushing seal. Very common in cars with over 150K. The bushing and seal can be replaced with the tranny in the car. Should be replaced together.

More importantly, before you shell out $450+ to replace the rear main seal - have you serviced your flame trap? The breather box? No clogs in either one or any of the flame trap related hoses, nipples etc.

In case you aren't aware of it; clogs in the pollution control system can cause leaks out of the oil cap, valve cover gasket, rear and/or front engine seals. If your distributor is in front (like a 240), also check for an oil leak out of a plug on the rear of the cylinder head. Check out the 700/900 FAQ.

Potentially save yourself some money by doing these checks. I've been down both the roads before...

The transmission has to be pulled away from the engine to replace the rear engine seal so it is a perfect time to replace the transmission seals. It would be horrible to get the engine seal replaced and have a transmission seal start leaking a couple of months later. Like you suggested it's a good idea to replace the trans mount at the same time. All of the seals and the mount are inexpensive so there is no good reason not to replace them. This is just my nickels worth(inflation you know).