I'm mid way through a transmission swap so the rear main is completely exposed, but I don't know if I should replace it. I picked up a new one figuring I would, but my brother told me he has read that a new rear main can leak since the stock one has worn a groove in the crank that the new one wouldn't completely fill. I can't tell for sure if the rear main is currently leaking or not. There was a lot of fluid in the bellhousing and under the transmission, but I think it's just gear oil leaking from the rather bad input shaft. I've never driven the car before so I couldn't say if it's losing oil over time. So do I go ahead and put the new seal in, or not worry about it?

 

 

Also, my brother said he found information about the separator plate gasket leaking and I might want to replace that too. Any opinion about that?

 

Edit: Just realized I forgot to include vehicle info. It's a 1995 Legacy Outback.

Edited February 13, 201115 yr by HankG

Rearb main NO - unless it's very, very obvious it's leaking. Because you're probably gonna cause yourself problems.

 

Baffle plate - I usually clean and reseal with Ultra Grey. A lot of folks get a new metal one with the matching new screws.

I should add that I put a few dimples in the metal housing of the seal trying to get a screw in before I stepped back and reevaluated. They aren't very deep at all, just the very tip of a wood screw. It doesn't seem like they'd be enough to hurt anything, but figured I'd add that just in case.

 

Here's a picture of what I'm looking at:

 

http://pages.suddenlink.net/hank-g/014.JPG

Edited February 13, 201115 yr by HankG

i cant see anything in that pic other than some type of sealant hack job someone put on the rear main seal. the seal goes on with a touch of oil only.

I'd say some one was into it already. The RTV around the seal should not be there. The seperator plate is leaking like crazy.

 

If you do change the seal, take some green socthbright and polish the crank seal area and then clean it well.

 

Lube the seal surface so it is not dry when you start it up.

The car has a practically brand new clutch and flywheel, maybe they worked on the rear main at the same time? I have no history on this vehicle beyond what I've seen from pulling it apart. Also, it looks like the rear wrist-pin access (is that the right name? the plate held in with two screws) is leaking pretty badly; is there something in there I should be replacing or resealing?

Use a Subaru seal only on the rear main. If the one in there looks like it could be aftermarket I wouldn't leave it in there. Given the sealant I'd be tempted to pull it and replace it properly but if it's not leaking and it's a Subaru seal then leaving it is an option.

 

definitely reseal the separator plate. subaru has an updated metal plate and screws to replace the cheap plastic junk if that's what yours still has.

 

as for that access screw, interesting. remove it, clean up the threads, and put some sealer on the threads.

Thank you for all the posts. I called up the dealership to ask for a price on the separator plate and also asked about the rear main and the guy recommended changing it. That combined with the fact that the sealant seems to point to this one not being the original, it seems like I'd be safer replacing it than leaving it alone.

the only rear main seals i've ever needed to replace is because someone else has a.ready done it prior. i've never had to replace an oem one.

 

i use a pvc collar and a block of wood to install the new one.

 

a real seal puller may be suggested to get the old one out.

 

good luck

Pop off that wrist pin cover on the left side and put a new O-ring under it while you have access. PN 806931070 It looks like it might be leaking. That rear seal has certainly been replaced. Hard to tell if it's leaking, but no sense in taking a chance on it. Clean out the seal bore and make sure it's 100% clean shiny metal before you put the new seal in. A little grease on the outside of the new seal will help it slide right in.

Very good info.

Thanks

 

 

Pop off that wrist pin cover on the left side and put a new O-ring under it while you have access. PN 806931070 It looks like it might be leaking. That rear seal has certainly been replaced. Hard to tell if it's leaking, but no sense in taking a chance on it. Clean out the seal bore and make sure it's 100% clean shiny metal before you put the new seal in. A little grease on the outside of the new seal will help it slide right in.