Rear Main Seal replacement

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Jul 1, 2008 | 11:11 PM

1974ta

Thread Starter

Melting Slicks

Joined: Feb 2004

Posts: 2,111

Likes: 32

From: Damascus MD

Rear Main Seal replacement

I have read about what to do but before I attempt this I would like to know what the risks are. What are the risks and pitfalls? 350 sb 4 speed, 4 bolt main.

Also, what type of sealant do you recommend between the cap and block where shown in the service manual? How much sealant?

I really appreciate all the input. You can see I am learning as I go.

Thanks,

Bill

PS- I still have been unable to get that darn balancer off. Someone said try an electric impact gun? I do not have any air.

Last edited by 1974ta; Jul 1, 2008 at 11:12 PM. Reason: Additional info

Jul 1, 2008 | 11:19 PM

Jud Chapin

Race Director

Joined: Sep 2001

Posts: 10,560

Likes: 439

From: Wellington, FL

St. Jude Donor '11 thru '25

If you are mechanically inclined, take your time, and get proper instructions, you will have no problem. For the pan gasket, I would suggest using the one piece Fel-Pro gasket and the same brand for the rear seal. Regarding the balancer, you will need a puller which you can borrow from Advance or AutoZone. Others will chime in on your other questions. Good luck!

Jul 2, 2008 | 09:36 PM

tnovot

Racer

Joined: Feb 2008

Posts: 497

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From: Streator Illinois

A lilttle Permatex or black RTV will work. Use just a very small dab. You don't want it to squeeze out and get in the area of the shaft and rubber lip on the seal. All you are providing for is a seal on the flat part of the cap.
Terry

Jul 2, 2008 | 09:48 PM

1974ta

Thread Starter

Melting Slicks

Joined: Feb 2004

Posts: 2,111

Likes: 32

From: Damascus MD

Thanks so far guys!

The instructions in the service manual say to turn the crank to get the upper seal in place. Is this correct or I have read that you can push up inb place with a brass pin or wooden dowel?

It also said you may need to loosen the main cap next the the rear as well to allow a little clearance.

Thoughts?

Bill

Jul 2, 2008 | 09:52 PM

tnovot

Racer

Joined: Feb 2008

Posts: 497

Likes: 0

From: Streator Illinois

Quote:

Originally Posted by 1974ta

Turning the crank will help the upper seal to move into place. It may go without rotating the crank - you don't want to damage the new seal tho.
Losssening the next forward cap is not a bad idea but doubt it would allow the shaft to drop enough to make much diffreence. Can't hurt to try - just remember to tighten and torque when done.
Terry

Jul 2, 2008 | 10:07 PM

frank1973

Advanced

Joined: Mar 2008

Posts: 72

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From: Yardville NJ

Let the upper seal protrude about 1/4" one side and the lower stick out the same amount opposite side. Helps to avoid leaks at the seams.

Jul 3, 2008 | 08:51 AM

Edzred72

Le Mans Master

Joined: Oct 2001

Posts: 5,943

Likes: 3

From: Wildwood IL

This is one of the first jobs I ever did on my car years ago.....it's easy.

Drop the steering by removing the power steering ram (if equipped) where it attaches to the frame (4 bolts). The whole assembly will swing down for pan removal.
Drop the pan...
Remove oil pump. Carefull...if original, those pump pick ups are pressed in. Also check plastic coupler that attaches the pump drive shaft to the pump. Could be cracked. Clean pump & pick up with solvent.
Remove main cap. Both upper and lower seals can be pushed out with a dowel/punch. Push up on upper seal a bit..grab with pliers on the protruding end and pull. Same with lower on cap.
Be sure seal is positioned properly. (see pic in instructions)
Upper seal will slide right in using the supplied plastic "shoe horn tab". USE IT!!!
Dab a "small" amount of high temp RTV on the seal mating surface. When installed, be sure both seal ends are even with the surface on cap & block.
Install cap...torque to spec...
Install pump...torque to spec.
Pan...torque.
Steer ram...torque...
Start her up!!!
Eddie