rear main seal popped out

[sirtokesalot]

i rebuilt the engine in my 2001 outback about 10 months ago now did everything had the block split new bearings and rings seals had no leaks for the first 9 months then it started leaking first slowly then massive amounts until today when i pulled it apart and found the rear main popped out and leaking was able to remove it by hand. why would the seal come out? should i be afraid it may happen again? i think if i remember right the rear main got messed up the first time and had to buy another one from local part place and was not genuine seal 10 months ago.

[Rampage]

PCV valve clogged? Too much crankcase pressure?

I was told by a mechanic at our local Subaru dealer to clean the hole in the block and apply grease to the crank. Then apply a thin coat of silicone gasket compound to the outside of the rear main seal with my finger and push it in until flush. Then wait for the silicone to setup before starting the engine. That has worked for me every time with aftermarket seals.

I found that the can from my friends spray gun fit the seal perfectly to tap it in on our EJ22. Be careful and do not push it in too far.

[GeneralDisorder]

We use NOK or Subaru OEM seals and have never had one pop out. 

One dirty trick I have used on seals is to coat the OD of the seal in loctite 248. You will completely F*uck the next guy though as the rubber on the seal will come apart before the loctite lets go. Real mess to clean up. 

GD

[idosubaru]

install carefully - the rear main is so much larger than other subaru seals it's easy to feel awkward getting it seated.  i've had them canted slightly at various points of install but never had one leak.

I've seen multiple old gen seals not mic to OEM specs and be too small and too large - mostly crank seals.  Doubt it's as variable with EJ engines and most of that was probably years ago, but OEM only for rear mains IMO. 

Mostly out of curiosity, I can't imagine this happened, but if the block is split is it possible for the case halves to be out by enough to infringe on seal seating?

[sirtokesalot]

i dont really wanna loctite it in place as id be the one to do it again if it needed to be done again. im also prety sure the block is fully together i did torque it to spec according to the service manual. i read a bunch of stuff about the oil drain could be plugged with rtv causing the oil pressure to push it out how likely could that be seeing as it took 9 months to push out the first time? i should have researched it before putting the new seal in i feel like i should buy another seal and pull it back out and check those oil drains at the rear main seal before i put the engine back in.

 

 

[1 Lucky Texan]

could oil pressure be high? I had a 78 Honda, had to put it back together after a broken TB/broken valve disaster, the oil relief valve stuck and it popped the seal on the oil filter.

 

seems unlikely to be something that would develop over months though.....

Edited October 7, 2020 by 1 Lucky Texan

[GeneralDisorder]

Oil pressure wouldn't affect the main and cam seals. Subaru's run high oil pressure anyway. 

GD

[sirtokesalot]

well i wound up pulling the new seal and checking the drain hole anyway for piece of mind. it was clear put another new genuine seal in and power washed the engine bay. im going to put the engine back in tomorrow.