The Stovebolt Site Forums The Shop Area Engine Shop 1953 GMC 235 Rear Main Seal

I have a 1953 GMC with a 1955 235 engine and the engine rear main seal is leaking. Is there an easy way the replace the engine rear main seal without removing the engine?

Yes. You'll need a Lisle # 27000 "Sneaky Pete" or equivalent.
Drain the oil and remove the oil pan. Pull the transmission enough to clear the input shaft from the pilot bearing/crankshaft. Remove the rear bearing cap and loosen the rest of the the main bearing caps so the crank drops just a little.
The Lisle kit has a corkscrew to screw into the old rope seal so you can pull it out. There is also a clamp on a wire with a removable T handle. Clamp on to the new rope, push the wire through, add the T handle and pull the new rope through. Set the new seal in its groove best you can with a wood or plastic stick, leaving 1/16-1/8" tag end. Snug up the caps that you loosened and cut the other end of the seal flush. Replace the seal in the bearing cap, leaving another 1/16- 1/8" tag on the other side from the first one. Torque the mains to spec, bolt the pan on with a new gasket, fill with engine oil, shove the tranny back in and go.

Fairly easy one day job with a helper.