Rear Main seal replacement on 72 Chevy

[Momboy007]

Hello All,
It seems the rear main seal is leaking pretty badly on the 72 Chevy Pick up, 1/2 ton with 350 motor and 350 Turbo transmission. What is the best way to replace this, is there a best known method for replacing this seal?
Thanks all in advance,
Rick

[Tx Firefighter]

Drop the oil pan and oil pump, remove the rear main bearing cap, fish the old seal half out and spin the new one in place.

Sounds easy when you say it like that doesn't it ?

Basically, you have to use a blunt curved tool to slide the upper seal half out of the block and the new one into place. It can be a bear if it's old and stuck.

[Momboy007]

Hey TX,
Can I drop the pan without removing cross members etc...?
Thanks for your help
Rick

[C20_Paul]

If you have a one-piece seal you'll have to separate the engine and trans to get it out. If yours is a two-piece do what TX_Firefighter said.

If you have the two-piece you may have to jackup the engine in order to slide the oil pan out from between the engine and the crossmember. Just unbolt the motor mounts and pick the engine up by something other than the oil pan and you are in business.

I'd also recommend switching to a one piece oil pan seal while you have it all apart.

[Tx Firefighter]

If you wind up having to jack the engine up off of the mounts, do two things, trust me here. One, unbolt the fan shroud from the radiator. Two, remove the distributor cap and lay it aside somewhere.

You will break one or both of them if you don't.

[Sinister]

Yes, you have to undo your motor mounts, jack or lift the motor, then put some 2 x 4's where the motor mounts are. You might have to turn the crank to clear the pan.