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Rear main seal replacement questions
Posted: Mon Jun 13, 2005 2:21 am
by vrg3
How do you remove the old rear main seal? I'm afraid to pry with metal tools because I don't want to mar the sealing surfaces or anything.
When installing the new one, do you pack grease or anything behind it? Or do you just coat the seal in oil and press it in? Will my thumbs form a sufficient press?
Thanks.
Posted: Mon Jun 13, 2005 2:26 am
by THAWA
A screw driver should work fine so long as you don't manhandle it. A little bit of oil around it should work nicely and no you can't just press it in with your finger. Best thing to do would be to buy the seal installer. If you don't want to I'm sure you could make something work. Is yours leaking or something? and have you looked at it directly to know that it's leaking?
Posted: Mon Jun 13, 2005 2:31 am
by vrg3
Thanks. I'm still really scared of doing it with a screwdriver, but I guess I'll try...
Maybe I'll try pressing it in using the flywheel... I could put the flywheel on and tighten the bolts evenly to push it in.
I don't know for sure if it's leaking, but it was definitely coated with lots of oily grime, and there's some oil in the vicinity. I've got it all opened up and a new seal right here, so I don't think there's any question about whether I should replace it.
Posted: Mon Jun 13, 2005 2:33 am
by THAWA
What does the separator plate look like?
Posted: Mon Jun 13, 2005 2:34 am
by vrg3
Which one is the separator plate?
Posted: Mon Jun 13, 2005 2:38 am
by THAWA
It's the big kinda parallelogram-shaped plate on the right side has I think 6 screws in it.
Posted: Mon Jun 13, 2005 2:39 am
by vrg3
Let me take a look; I'll be right back.
Posted: Mon Jun 13, 2005 2:41 am
by vrg3
It's got oily grime on it too, particularly the outboard portion.
Posted: Mon Jun 13, 2005 2:46 am
by THAWA
I'd be willing to bet the oil is leaking from the separator plate and not the Rear main seal. I'm not going to say it's impossible for the rear main to leak, but it's more likely for it to be a problem of the separator. If it were me I'd just replace the separator and put some threebond on the mating surface, but I'd hate for that not to be the problem or them both be leaking and have you have to go through this again.
Posted: Mon Jun 13, 2005 2:54 am
by THAWA
Also I don't think using the flywheel would work. I think theres a few mm of clearance between the flywheel and the rear main.
Posted: Mon Jun 13, 2005 3:23 am
by vrg3
Well, I've just replaced the main seal. You're correct about the clearance; I used the flywheel to get it started and then finished it off with rubber mallets and whatnot.
I'll check out the separator plate too. Thanks.
Posted: Mon Jun 13, 2005 5:02 am
by free5ty1e
Thats what that thing was. Yes, my separator plate was grimy and oily as well, but my rear main seal was fine just fine. Too bad I didn't have time to acquire a replacement plate or gasket or whatever it is behind there that seals.. but it wasn't too bad.
Why is there a plate there might I ask?
Posted: Mon Jun 13, 2005 5:20 am
by THAWA
It's supposed to remove the oil from the blowby gas.
Posted: Mon Jun 13, 2005 5:23 am
by free5ty1e
the hell you say. Well, it was definately removing oil from the engine at some fathomable rate. I'm not dropping the tranny again anytime soon, lol
Posted: Mon Jun 13, 2005 5:40 am
by THAWA
Hey, as long as it's not in the blowby it's doing its job, right?

Posted: Mon Jun 13, 2005 2:37 pm
by free5ty1e
Thats a good way to look at it. Makes me feel way better about not doing something about it lol
Posted: Tue Jun 14, 2005 2:32 am
by Legacy777
Just to add.....you can use the old seal to drive in the new seal. that's what I did.
Posted: Tue Jun 14, 2005 4:48 am
by 206er
I used a block of wood and a deadblow.
Posted: Tue Jun 14, 2005 6:29 am
by vrg3
Oh, didn't think of that.
I found this PVC pipe cap at the hardware store that had almost the exact same diameter as the seal. The mallet worked well on that.
Posted: Tue Jun 14, 2005 2:32 pm
by greg donovan
vrg3 wrote:Oh, didn't think of that.
I found this PVC pipe cap at the hardware store that had almost the exact same diameter as the seal. The mallet worked well on that.
that is essentially what the special subaru tool is that is used at the dealership.