Guess the oil leak?

[fairlaniac]

I need this for therapy :-)
My self built 47(484) would leave a drop or two (dime size) oil leak under the bell housing shortly after my first start. It was frustrating but these things can happen. Then it didn't take long until it was a quarter size and now about 150-200 miles on the new build the oil slick is now a 3" diameter spot. So I figure in a month or two (over winter) I'll pull the trans, bell, etc... However I am trying to diagnose what it may be. I brushed it off as a rear main seal issue. However the oil appears to form a line at the trans and scattershield and drips forward down the slope of the scattershield and down the vertical bolt flange then to he ground. I also am getting drips from the back side of the fork onto my headers. I'm trying to figure out what could cause oil to get past the flywheel & clutch onto the fork. I can start the car and the oil will develop in 5 minutes. I'm use to seeing main seals drip in front of the flywheel and block plate and drip down. It baffles me how oil gets to the transmission front flange?

Here are some pictures of the leak if you can make them out.




Thanks!

[SSdynosaur]

Have you positively identified the leaked product as engine oil because your tracing description sounds like trans input retainer gasket and/or bolts leaking trans lube.

[fairlaniac]

I've put dye in my engine oil and on a black light the spot on the floor lights up.

[Stangman]

I agree I don’t think it’s oil. Not leaking from there. Input shaft gasket-or a crack-or bolts loose. Main shaft seal leaking. I don’t see how it could get that high to leak in that spot

[GerryP]

Most of the time, it's the valve covers or the rear China wall.  It's doubtful it's the rear main since you get a lot of oil out of that.  See if your dye shows up at the rear of the engine.

[fairlaniac]

[Stangman]

Now you can see it coming around from that pic.

[fairlaniac]

Now you can see it coming around from that pic.

The dye is in the engine oil.

[Nightmist66]

I'm with Gerry, check the rear China wall. Try to get a mirror back there.

[fryedaddy]

valve cover leaks can travel to other areas

[fairlaniac]

I'm with Gerry, check the rear China wall. Try to get a mirror back there.

Thanks but I have checked the obvious leaks externally. It would be difficult for oil to drip from the China wall and get inside to the point where the T/O bearing is mounted on the fork. As indicated, I have oil coming down the back side of the fork and dripping on the header.


Thanks,

[Gregwill16]

If definitely inside the bell, may be one of the plugs or the relief valve in the rear of the block.

[fairlaniac]

If definitely inside the bell, may be one of the plugs or the relief valve in the rear of the block.

That's what I'm hoping. Easy fix.

[TomP]

I would still guess valve covers. Before putting the aluminum ones on my Fairlane i fought that with the chrome valve covers. Was damned sure it was the rear main seal... but that didn't fix it. Took the intake off and resealed that (used cork ends this time)... nope, after having the bellhousing off a second time (and headers to get it off) i noticed a very slight wet trail on the back of the head. The valve covers leaked and dripped off the middle of the bellhousing. Sure felt dry from above when i'd checked.

[fairlaniac]

I would still guess valve covers. Before putting the aluminum ones on my Fairlane i fought that with the chrome valve covers. Was damned sure it was the rear main seal... but that didn't fix it. Took the intake off and resealed that (used cork ends this time)... nope, after having the bellhousing off a second time (and headers to get it off) i noticed a very slight wet trail on the back of the head. The valve covers leaked and dripped off the middle of the bellhousing. Sure felt dry from above when i'd checked.

Tom, from under the car while on the lift I can see clearly to the heads and there is not one drop of oil from the valve cover. With a penlight black light and mirror. I can see the dye light up inside the bell and all the way up to the t/o bearing on the fork.

[JERICOGTX]

With a block plate, it's odd that engine oil would be getting into the Scattershield. They are pretty much sealed off to the engine. I had/have the same issue on my car, and figured out that it's the input shaft seal, in the throwout bearing collar, on my jerico transmission.

[shady]

Some plates have holes for gallery plug plus the big hole for the cam plug which are all above the crank throwing oil everywhere.

[6667fan]

If it is the galley plugs the migration is extreme. The clutch will be risking oil contamination. Any oil on the engine side of block plate?
The galley plugs have a dedicated pitch to them. Other plugs will work but an extreme sealant like Blue Block is what I like for sealing those.
I’m glad you think ripping the trans/clutch down is easy, lol. At least you have a lift and a trans jack/support I hope.

[cjshaker]

Some plates have holes for gallery plug plus the big hole for the cam plug which are all above the crank throwing oil everywhere.

^^This...
As far as I know, all the Lakewood plates have those holes, and they will allow oil to be slung around and past those holes. And yes, if that happens, it will ruin a clutch plate within a fairly short time period. If Doug is sure that the oil is from the back of the engine, and he has a Lakewood plate, or similar plate with holes, then it would be wise to get it fixed as soon as possible. Although I'd certainly make sure that was where the source was from, because I hate pulling transmissions.

Edit to add that I have no idea why Lakewood put those holes there. You can't reach the plugs with the flywheel in place, and if the flywheel is off, there is nothing holding the plate on. Makes no sense to me.

[HarleyJack17]

Most likely it is oil galley plugs or cam plug.
BUT, isn't there the off chance that the plug in the crank could cause an oil leak as well?   

[fairlaniac]

If it is the galley plugs the migration is extreme. The clutch will be risking oil contamination. Any oil on the engine side of block plate?
The galley plugs have a dedicated pitch to them. Other plugs will work but an extreme sealant like Blue Block is what I like for sealing those.
I’m glad you think ripping the trans/clutch down is easy, lol. At least you have a lift and a trans jack/support I hope.

Jim, I've got the lift and last year at Maple Grove's swap meet my buddy picked up a trans jack/support that I can use. I say easy fix because those are the games I must play with myself when motivation fails :-)

Today I ran the engine while the car was up on the lift and watched the oil. It ran down the front of the block plate and the mating surface of the bell and trans.


I won't be bringing the Fairlane to FERR next week. I'll pull the trans and bell after that.