rkk69olds

I started buttoning up the engine today after my cam and head swap. I was wiping down the block to prep it for paint and while wiping the oil pan I saw a small driip coming from the rear main seal. The engine has been in the engine stand for a few weeks and no oil has dripped but understand there has been no pressure on the system. Since I still have the flywheel on I had to put a mirror to see and it looks like the seal is bulging slightly on the bottom. It's a neoprene seal and only has 300 miles. Should I go ahead and change it while it's out or is a smal drip acceptable? Who makes the best seal and oil pan gasket?

Thanks

Rickman48

For the 1/2 hr it'd take to fix it now, I'd think it'd be worth it, vs pulling the motor if it starts 'dumping' at a later date!
Or even fixing it in the car, on your back, with bad lighting, and oil dripping down your back!
Guess I mean - DO IT NOW!!

rkk69olds

Thought so too, but had to ask.....nothing like a little workscope creep!

Thanks

MDchanic

Agreed. Change it now.

It's the Ford "Y-Block" seal, if I recall, 239, 256, 272, and 292cid, but not 312.

I believe the BBO seal is the Ford "Lima" block seal - 370 truck, 429, and 460cid, if I'm not mistaken.

- Eric

cutlassefi

For a small block you can also use a 258 AMC seal but cut the ears off.

rkk69olds

Could it just be the oil pan side and not the portion that goes under the main cap. If so I can just get an oil pan gasket set. I really do not want to pull any bearing caps. How difficult is it to slide the new seal under the bearing cap w/o messing it up?

Thanks for the help

captjim

Not possible. The seal fits in a groove in the block and cap.
IIRC, Fel-Pro part # for the 290 seal is B/S 6141

Rickman48

As my Daddy once said;
"Do it right, or don't do it at all!"
Why try to shortcut anything while it's out of the car??

F-it, just hit it with carb cleaner and silicone then!!!!!!!!!!!

rkk69olds

Actually, instead of trying to short cut anything, I am actually trying to establish the root cause. Is it the oil pan gasket, is it the rear seal, etc....also, I want to avoid pulling the caps as I do not want to open another can of worms. I have alot of money invested and don't short cut anything. Just trying to understand all possible options. Thanks for pretending to know anything about me.

oddball

by "slide the new seal under the bearing cap", do you mean the oil pan gasket? Folks assumed you meant the crank seal.
The lip isn't huge, so you might be able to loosen the pan and work out the old gasket and put in a new. You'd most likely damage the cork rail gasket (assuming it's cork and not the fancy steel core ones) and cause more leaks, so might as well just drop the pan and replace all of that gasket set.
You don't need to remove the cap just for that.

joesw31

Use a ear cotton q-tip, and rub it around the crank shaft and the seal and see if oil comes out, and the same between the rear main cap and the oil pan. More than likely it is the seal bewteen the cap and oil pan. Also pull the flywheel to get a better inspection.