Rear Main Seal

[cowsaredelicious]

Ok, I'm sure this has been asked before but I believe I have a leak at my rear main 1960 348 engine. Can it be done in the car?

Tricks? Tips?

Any help would be appreciated.

 

[Fathead Racing]

The 58/60 shop manual says yes. You have to have the crankshaft in a certain position to clear the counter weighs to pull the pan. Pull the rear main cap and you can push the old seal top half out with the new seal. I always clock the seal ends so they do not line up with the parting line of the rear cap. Theoretically you should be able to loosen all the main bearings to give yourself some wiggle room. I've done this a couple of times many moons ago.

 

[poison ivy]

after you loosen mains, push seal out of groove with cotter pin, in crank oil hole,with loop of key sticking out. rotate by hand.

 

[La Hot Rods]

The pin in the oil hole will push the bearing half out not the seal.
When you roll the new seal in you want to push it against the crank so the edge of the block doesn't shave off the back side of the seal.

 

[models916]

Don't forget the rear small things.....two added rubber pieces that go with the rear main, lots of guys forget them.

 

[chuckl]

The 58/60 shop manual says yes. You have to have the crankshaft in a certain position to clear the counter weighs to pull the pan. Pull the rear main cap and you can push the old seal top half out with the new seal. I always clock the seal ends so they do not line up with the parting line of the rear cap. Theoretically you should be able to loosen all the main bearings to give yourself some wiggle room. I've done this a couple of times many moons ago.

I am having the same "leaky" problem from the rear seal. Is it necessary to loosen all the caps? Will the crank sag enough if only the last two/three caps are dropped? My engine is a 61 truck block---tri-power, with a Centerforce clutch and M-21. I have done this on SBC, using a chiseled-pointed toothbrush handle to start the old seal rotating out. Any reason to/not to lube the outside of the seal halves for easier insertion. I usually lube up other things for easier insertion--it seems to help.

 

[La Hot Rods]

If you were to loosen the main caps you would have to loosen all of them.
I have only had to loosen all the mains to replace a rope rear main seal.

 

[MRHP]

I would pull the motor, myself. Much more control over the quality and easier to work off of an engine stand. Just because you can, does it mean you should? I like to do crummy jobs only once.

 

[Deadwolf]

I would pull the motor, myself. Much more control over the quality and easier to work off of an engine stand. Just because you can, does it mean you should? I like to do crummy jobs only once.

Above is what I would do!
The engines in these older cars come out way easier than the engines in modern cars and trucks. If you have a couple of guys that know what they are doing and some beer you can generally pull the engine, replace the seal, and reinstall the engine easily on a weekend with the right tools.