I think its time to replace my rear main seal. Ive done em before in 302's and they were fairly simple. Are these the same or will it be alot more difficult. Knowing my luck it wil be a pain in the ***. So if they are different than the 302 i will have no idea where to start so details would be great. Thanks

 

They are all the same, just remember to offset the seal before bolting the main cap back on.

 

Remember the FE is a deep skirted block. The seal will be harder to replace.

 

If it's a old original it could still be a rope seal, no way in hell to remove the top half unless you pull back the tranny then lower the back of the crank.
This still would be a battle working with dental tools not scratching the crank unless you wrapped the journal with brass shim stock first.
You damn sure it's not a valve cover or back of the intake manifold leaking?
Don't leave out a oil passage plug at the back of the block or the cam plug.

 

i did this on my 67 428.
it was a rope seal in there.
replaced with the neoprene.
really did not have to much trouble getting the rope seal out.
w/o moving tranny.
the end seals on the cap were sure a different thing.
been a few years but remember driving finish nails up in them to make a tight seal.

 

Your got lucky, the two I removed they were rusted in place.

 

when i took out the cap bolts, i for sure remember water coming out. and it stunk to high heaven.
that had me worried for a while but...no problem . these engines do like to leak from intake and valve cover.
so
check the easy stuff first.

 

Agree with Carl, The FEs are not known for rear seals leaking, but the intakes sure are, and the rear gets blamed because the oil runs down.

John

 

I'm at over 277K miles and 19 years use without a rear main leak and this is a rope seal. I used a aluminum plug 4" long that I cut .005" undersize where the seal runs then seated the rope into the block later cut the excess rope away on the block. Same tool and technique applied to seat the rope into the cap.
If you use a rolling pin technique you may crush the rope below the crank journal contact area causing a leak if the seal doesn't swell up enough, why I know this I did that technique back in the late 60's.

 

Well its a rebuilt motor, it has less than 12k on it but it was sitting for a while. Im gonna check the intake and valve cover and hopefully that is it. Now you guys say remove the caps, remember ive only dealt with 302's never these big blocks. With the 302's all i did was pull the tranny, clutch, and flywheel and the seals right there.

 

Different Aminal altogether.

John

 

Yeah i realize that.....thats why i need to know how to do it.

 

Are you thinking that you may not have done it correct the first go around?


John

 

I havent done it before, i didnt rebuild the motor i bought the truck with it in it.

 

the one i have had the pleasure of doing on was not a truck.
so the removal of the oil pan was real easy. you would have to jack up the engine on a truck a little bit to get the pan off.
that is why you want to make this the last effort before you check out all the rest of the options. i think once you get the pan off it becomes clear what all are saying. the rear main cap it really part of the block. all the seals are in and around this rear main cap.
you know i had a samll leak this past few weeks and i hate oil leaks. found out it was the valve cover again...they are aftermarket covers.
hate to tell you how many times i pulled the intake to get it to seal.
then
there is the oil pan....
then it could be the area between the heads and block since fe pump oil thru the head.
find it oozing out when the engine is running. but have to get into some contorted positions to see it.
have seen all these on my fe's.