Pictures of how I Replaced the leaky Oil Separator Plate and Rear Main Seal on the Subaru Legacy Outback 2.2 engine.
The Oil Separator Plate is on the rear of the engine, hidden behind the flywheel. It doesn't hold in the oil. Originally designed in plastic, which leaks. Then redesigned in aluminum, which leaks. Then redesigned in steel, which so far isn't leaking, knock on wood.
Back of engine is oily from a leak. The oil leak is from the from the oil separator plate.
The Rear Main Seal (RMS) and the transmission input shaft seal both look good.
I will change the oil separator and the RMS while I am in here.
I removed the oil separator plate and cleaned the mating surface with a plastic dish washing scrubber.
Here is the new oil separator plate complete with subaru part number. $25 from the dealer with new bolts. This is the third redesign. The first was plastic, the second aluminum, and this one is steel.
The new plate installed, using
Permatex high temp RTV silicone gasket, and blue thread lock (I think I should have used the anaerobic here, same as on the oil pump). The odd bolt with thread lock already installed went into the top left hole with the arrow. Bolts use 4mm allen. Had to scramble to find one as the threadlock was drying.
Removing the rear main seal. Installed new one using a block of wood and rubber mallet to seat it.
I read in a motorcycle repair guide that all seals need grease on the inside of the seal before installation. The Subaru service manual says, "Install oil seal." All I did was use a tiny bit of clean oil to help it slide in. I will have to wait and see how it works.
- Next I sold out to make 02¢
so I can fulfill my lifelong dream of owning a 1986 944 with blown head gaskets.
But no minivans!
- Then I finished my beer.
It has been 3 months and all looks good! However, it looks like there is another leak coming from the oil pan. Oil is blowing back from the oil pan, to the bottom of the flywheel, onto the exhaust, and onto the transmission. There is much less oil, so it is likely that the rear main seal and / or the separator plate were also leaking. They are notorious for leaks. But we all know that everything leaks on a Subaru. This oil pan leak is on my to do list.
7 months. Cam looks good. Water pump looks good. Oil pump looks good. No leaks there. All is dry and slightly dusty.
There is no burning oil on the exhaust. So that is way better, but:
The oil pan is slightly oily around the seal. There is a small amount of oil under the flywheel, just behind the oil pan. The oil is black and dry, so the leak is very slow. But it still has the potential to get blown into the bell housing and onto the clutch. AGAIN. We're in an apartment right now and can't dig into it. We will wait and see.
Over two years since change. Just changed the leaking oil pan gasket. Impossible to tell if the RMS or separator is also leaking. They are just too close together. Maybe if the oil pan leak is fixed, I will be able tell if there is a leak coming from somewhere else.
Three months since I changed the leaking oil pan gasket. All is dry and a bit dusty. Really. A subaru with no oil leak. I know. It's crazy.
The oil pan is mostly dry. Everything everywhere else is oily. Sigh.
Donate to CharityIf this site has helped you, or even if it hasn't, please help care for abused and neglected children by making a donation to The Valley of the Moon Children's Home. That's right, abused and neglected children. Visit their website and try not to cry, you cold hearted bastard. Their site talks about how they achieved their goals and built a new home, but that was years ago. They still need cash to take care of all the kids there. Breaks my heart and pisses me off.
Think: Cars are expensive, powerful, and heavy. Before I start work, I face the possibility that I will destroy my vehicle, my own life, and innocent pedestrians' lives. If anyone messes with a 4000 lb machine capable of 100 mph, these are real possibilities. If I get in over my head, I call a professional mechanic. The information on this website is provided only for entertainment purposes, and it is not intended as advice on how to service a vehicle. For all you know I made this up. Don`t believe everything you read on the internet.
Disclaimer: The technical information in these documents is provided without any warranty whatsoever and at no cost. All information is in general terms and is not meant to apply to your particular situation, be current at the time you read it, or even be correct in the first place. Improperly maintained vehicles can lead to serious injury, death, or unavoidable accidents. The author is not responsible for any errors on this site, and does not make any claim at all about the validity, safety, or veracity of the information contained on this website. Any work you choose to do or not to do on your vehicle is done at your own risk. The information on this site is not intended to serve as a replacement for professional advice, professional workmanship, dealer service, union labor, or psychological counseling. The author disclaims any and all liability directly or indirectly arising from the application or use of any information or idea contained on this or any other web site. By opening this page, you agree to never sue anyone ever or allow anyone to be sued on your behalf. The appropriate professional should be consulted regarding your specific condition. BeerGarage.com does not take responsibility for the information posted on other sites to which it links.
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Last modified: 11/21/2014