Crankshaft Rear End Oil Seal Leaking - thoughts please?

[ilib11]

Hi All,

Got some oil drops on the floor (yellow ones) and diagnosed with a leaking Crankshaft Rear End Oil Seal..... Got told that is a sizable and labour intensive work ( need to got transmission out etc....). Has anyone had such experience?

Not sure if I got enough time and resources to do that right now.... Is there any band-aid solutions like a oil stop leak additive that would buy me some time before it gets fixed properly?
Also is that a sign the car is going out its life (200k on the odometer) and just more bigger troubles just around the corner?

Appreciate your thoughts on this.
Regards, ilib11

[bigBADbenny]

It’s a common issue, generally known as the *rear main seal*.
There’s no Band-Aid solution, just get it done by a mechanic experienced in Subarus.

Correct installation of the rear main seal requires a specific Service Tool to set the specific insertion depth of the seal, or observation of that consideration if using conventional methods.
The procedure of course is in the FSM factory service manual, using the service tool, oem or aftermarket, eg company23 etc.
Use only OEM genuine gasket and prepare the area carefully.
Insert it too far and it will leak oil and or block internal passages, not enough and it might potentially fail prematurely.

I prefer to think of bigger jobs as opportunities for other maintenance and upgrades.
That’s eg resealing the rear AOS plate, replacing reverse and or neutral position switches, inspect CV boots, upgrade gearbox engine & pitch stop mounts, inspect flex plate or replace/upgrade clutch, etc.
I’m gen4 GT so I went with a DCCD 6mt, exedy HD clutch and lightweight flywheel, but next time (very soon lol) I’m going back to a stock flywheel, stock clutch, as for me, those “upgrades” simply aren’t required for my mods and driving requirements.

If you have engine oil further up the bell housing area, above the rear main seal, check the two block pcv breathers (ej20x/y & 255) : if the hoses there (centre breather & pcv sump stack tube) are cracked, you’ll find leaking oil on the top rear of the block and persistent negative fuel trims.
A leaking turbo oil drain is more likely to drip oil onto the crossmember and driveshaft area, but is still a consideration.
A blown rhs inner cv boot will create a mess in the area but the grease is heavier and has a distinct smell to it.

Essentially just go with a mechanic who has experience with this job, who will warranty the work. Discuss these considerations with them prior, get quotes. It’s likely to cost you less in the long term.

[ilib11]

Hi bigBADbenny,
Good to hear from you, yet another useful reply!
I asked at the service what else typically done with the rear main seal.
I know are couple of technology plugs at the engine that could leak too - one cover looks like AOS you mentioned.
My car is auto so I asked if anything at trans side needs to be done - like an oil seal there. They said it never leak.
as far as I understand, not much of upgrade on auto trans either - unless it is massive

Sure will check the PCV and breathers - thanks!
Not sure about turbo oil drain - on GenV turbo is somewhat under the engine and on a front side
So will do more investigation.
BTW, can be an engine oil sump leaking too?

Regards,
ilib11

[bigBADbenny]

If you are at all unsure, just clean the affected area really carefully and whilst the car is on stands or ramps, maybe try idle the engine and just keep idling until evidence of the leak reappears not ideal and you’ll want to do this in an enclosed area for ventilation, but you never know half an hour to an hour of idling might reap results.

So if you really want to be sure you can either use a special dye in your engine oil, or use the bright green Fuchs engine oil and get an LED UV torch, eg via eBay, that will really help spot where the leak is coming from: assuming you’ve cleaned the area thoroughly.