Rear main seal replacement information

  • 51,000 MILES

I just rebuilt my 4.7L 289 out of a 1968 mustang and initial start/warm-up went smooth except my rear main seal doesn't seem to be holding. I don't own a engine or car lift and I was wondering is the a feasible way to replace the seal without pulling the engine? Can you loosen the main bearings and lower the crank enough to replace it? Or lower trans?

Do you
have the same problem?
Tuesday, November 15th, 2011 AT 4:26 AM

1 Reply

  • 29,104 POSTS

That should be a two-piece rear seal. There's a tool to remove the upper part. You remove the rear bearing cap, then thread what looks like a pick but it has a screw thread on the end, into the end of the rope seal. If you used a rubber lip seal, you should be able to grab the end with a small needle nose pliers. Having a helper turn the crank by hand while you pull on it may make the seal come out easier.

To run the new upper half in, the tool looks like a wire screen formed into a tube, with a single wire for pulling. You feed the wire into the slot, then pull it out the other side. As you continue to pull on it, it acts like a "Chinese finger" and pulls tighter to grab the seal and pull it through. Be sure to lube the new seal with oil.

Was this
Tuesday, November 15th, 2011 AT 4:37 AM

Please login or register to post a reply.

Recommended Guides