Front Crankcase seal keeps coming out!

mike1978

Hi,

I had a bad oil leak from the timing belt covers recently so i took them all off to have a look. Once i`d got the crank pulley and sprocket behind it off, i discovered the old crank seal was protruding from the crank case and the front had worn off revealing the inner steel ring.

So i replaced it yesterday drifting the new seal right in seated right. I drove it this morning and its leaking more than ever. I `ve just taken it all off again to discover that my seal has done exactly the same thing - the seal has moved so that its protruding further than the case- i`ve taken some photos -

i took it out and it all looks pretty clean inside - there doesnt appear to be any endfloat.

here`s the seal -

did i install it correctly? i put some grease round the edge of it, then drifted it home carefully until it was seated back against the crankcase. it then sat inside the recess with a 2-3mm to spare before the edge of the crankcase.

should i have not used grease and maybe engine gasket sealant or something maybe?

any help would be great:)
cheer,s
mike

rjes · Posted: Wed Sep 03, 2008 6:39 am Post subject:

Any luck finding out more from Subaru forums / dealers, etc?
_________________
Regards,

Richard,

R J Engineered Solutions
Quality Subaru Powered VW Components
www.rjes.com

mike1978 · Posted: Wed Sep 03, 2008 7:44 am Post subject:

hi richard,

i had some luck, although haven`t quite got everything back together yet. This is a relatively common fault apparantly.

If you remove the oil pump from the crankcase, there is a plate on the back screwed on using about 5 countersunk screws. Over time, these can come loose. Someone suggested i check these. I took the pump off and 2 screws were hanging out, one was loose and only two were in tight.

Whats happens, is pressurised oil leaks into the cavity behind the crank shaft seal and pushed it out.

I `ve put the screws back in with some locktite, refitted an original seal and refitted the timing belt. Haven`t had chance to finish getting it all back together. I hoping it won`t blow out again after 40 miles or so!

Here`s the link to the thread on scoobynet if you`re interested. They`re quite helpful if you don`t mention its in a VW!

http://bbs.scoobynet.com/general-technical-10/709279-front-crank-shaft-seal-keeps-coming-out.html

cheers,
MIke

rjes · Posted: Fri Sep 05, 2008 5:48 pm Post subject:

Hello Mike,
I know the screws you mean. I had a look at a spare pump I have lying around when you mentioned this the other day, but didn't want to take them out. The pump came off something like a 20,000 mile engine, and came in with a job lot of spares I bought which were left over after someone fid a 2.5 conversion on a turbo. The pump looks like new. If it was oldkink I'd have pulled it to pieces out of interest!
The explanation of the problem makes sense - I was sure the pump woldn't be designed so the seal was retaining oil pressure. The shouldn't be coming out again with Loctite on them.
The more worrying part of this problem is that the plate is the back of the pump chamber, so if it's loose, the oil which gets out will no doubt reduce the pressure available where it's supposed to be. Hopefully you caught it quick enough!
_________________
Regards,

Richard,

R J Engineered Solutions
Quality Subaru Powered VW Components
www.rjes.com

rjes · Posted: Fri Sep 05, 2008 6:05 pm Post subject:

Just read the Scoobynet thread. Usually you wouldn't oil / grease the outer diameter of an oil seal, and it shouldn't need any sealant either. They're intended to be fitted dry. However, I've refitted them into oily housingd before and never had one come out. Pressurisation by the (internally) leaking pump will be the cause.
Also, the aftermarket seal you bought will almost certainly not be a 'copy' (as in a, lower quality part made as a cheaper replacement for Subaru's) as such, as someone mentioned. Oil seals are available in standard ranges as industrial components (from bearing suppliers, etc). The one you got will almost certainly be an off the shelf item from a range of seals, in a size matching whatever Subaru used. All the branded ones are made to the same standards. No doubt there are some unbranded ones out there though, like the crappy looking wheel bearings in the kit which I ordered fron G+S.
_________________
Regards,

Richard,

R J Engineered Solutions
Quality Subaru Powered VW Components
www.rjes.com

mike1978 · Posted: Sat Sep 06, 2008 8:31 am Post subject:

i ended up fitting a genuine subaru seal anyway - will finish putting it back together today. I killed 2 birds with one stone by replacing a noisy idler sprocket while i was there too.

yes - i wondered about losing oil pressure - i mentioned my idle kept dropping to 400 rpm then recovering - this seemed to be getting very slightly worse recently and i was wondering if this was linked. Like you said, hopefully i caught it in time.

just got to get the exhaust back on - waiting for rain to stop as i don`t like lying in a puddle of water doing the job!!