My Sub must be haunted - a mysterious oil leak appears under the transmission that never goes away.

 

I have a 1993 Loyale 2wd, 5speed, non-turbo, 153k. It was oil-free last year and ran fine, but suddenly developed an oil leak a few months ago. I thot it was the rear main seal so replaced it and the clutch. It still leaked. I took it to a tranny shop and he verified it was tranny oil leaking. I took the tranny apart and replaced the main shaft seal (with original Sub part) and sealed the halves together with sealant. It still leaked. I took it apart again, double-checked the main shaft seal for damage or alignment, used Subaru sealant on the case, then reassembled. It still leaked. I then replaced the 2 axleshaft seals and o-rings (Sub parts again). It still leaked.

 

The oil pools under the bell housing and on top of the p-side crossmember and is wet on top of the p-side drive axle boot and on the cat (making the smelly). There is nowhere else I can see where tranny oil could leak. I can only guess that it may be leaking from the filler tube because the dipstick is missing a washer? Or is there a way to develop internal pressure inside the tranny causing oil to blow out the new seals? The d-side area is dry.

 

Can anyone figure this 'ghost' out?

input shaft seal

If the mainshaft bearing has any play up/down or side to side, the seal will not work properly. The best way to verify a leak is go to Napa and get a bottle of UV dye and one of there cheap UV lights. Add the dye to the tranny or the engine, but not both. Use the UV light to track where the oil is coming from. If you add it to the tranny and get no reaction from the UV dye and the light, then add it to the engine and try again or vice versa.

Power steering lines leaking? They are in the same area.

Thanks for the responses.

 

The input shaft seal is the one I replaced. I set it into place carefully fully oiled on the lips and placed the 2 case halves together carefully. If it's leaking then I don't know why.

 

I actually wento NAPA and bot the UV fluid yesterday. However, I realized that using it would only cause the fluid I already see accumulating on all the surfaces to light up. If it's leaking from the input shaft I won't see the trail because it's covered by the bell housing. The tranny guy said yesterday that the 2 axle seals look dry even though there is oil splashed all around them.

 

It's not the power steering fluid because that level is always full but the tranny fluid is the one that goes low after awhile. Plus the tranny guy examined the leaking fluid and verified it was tranny fluid.

 

It's still acting like a ghost. I'm thinking it's excessive pressure inside the tranny causing oil to blow past all the seals? Is there a vent somewhere in the tranny? The dipstick doesn't appear wet on the outside.

IIRC, the dipstick tube is the vent, but I could be wrong. It is held in by that spring action.

 

Options? Clean it up at a car wash or such and use the dye.

 

Have you tried putting fresh cardboard under it and observing what drips where?

 

You do have that little cover plate on the bottom of the bell you can remove, right?

 

It can be frustrating...It took me a while to track down two different leaks in a C4 Ford AT. I ended up power washing it then used cardboard under it. Then reading glasses and a flashlight. Made it crystal clear.

 

Doug

Ok, I dyed.

 

Actually I'm still alive but I did the UV thing and shined the light on the tranny. The oil is clearly seeping from under the bell housing in little rivulets and splashing onto the driveway and some onto the right axle and catalytic somehow. There is nothing coming from the axle seals on either side. And I only poured the UV fluid into the tranny so it's not engine oil. Since I already replaced the input shaft seal and used Subaru sealant all around the casing, where else could it possibly leak from that area???

 

I'm totally flummoxed, baffled, and frustrated.

 

Any ideas?

What type of transmission casing sealant did you use?

If the mainshaft bearing has any play up/down or side to side, the seal will not work properly.

 

???

 

Replaced seal, but did you replace the bearing?

 

Wobbly shaft will kill a new seal.

input shaft seal or side seal (to the cv joint.)

As I said in my post, I used Subaru sealant (the expensive one) and it's not the side cv seals that are leaking. It's clearly coming from inside the bell housing and tossed around outside it. I guess it could be a wobbly bearing and that would cause it leak there, but I set the bearing into the inset as instructed and the case halves meshed perfectly. I turned the shaft manually and didn't detect any wobble. Is there any other way to test for wobble with the tranny installed?

 

Thanks for you help.

I'm having a similar problem (and HAD a similar problem in my XT) in my Loyale (91, 2WD, 122K 5 speed) but the top of the motor is "moist" and I have fluid pooling near the bellhousing and fluid underneath by the CV axle seals (new) and drain plug (JUST cleaned the area and pipes to see if it was leaking, but didn't use a new copper gasket.. my awesome Subaru Parts Dealer couldn't get... ) the tranny fluid is remaining solid as is my PS.

 

However, when it gets cold, my PS pump is starting to chirp.. even thou the fluid is new (swapped at 114K for 120K service). I'm going to pull the filter thing and check the REAL level. The little filter thing told me my pump was full on my XT when it was BONE DRY (even thou it was leaking and was already shot... thanks P.O.)

 

Pull the filter and then check the level.