A Stovebolt Tech Tip!

	Rear Main Seal Replacement
*By Robert "Oly" Oeleis*

Got those depressin' oil-leaking blues? Does the ole drip - drip-drip just emabarass you to death at the Cruise-in night? That old rear main seal just not doing it's job, is it? Well, here's Oly to tell you how to do it right and stop the oil drain!

I have seen over the last year that many folks have in-line sixes with rear main seal leaks. I've sent this to many of them. It's so easy it's "blonde" proof! Please print or copy these instructions and have them with you when you do this. There are two sets of instructions: one for original, wick-type seals; and the other for modern neoprene seals.

Rear Main Bearing Oil Seal Replacement

Wick-Type Seal

Remove oil pan and oil pump.
Remove rear bearing cap,discarding lower seal.
Loosen the remaining bearing caps to allow the crankshaft to drop a slight amount. If the crankshaft does not drop, place a lever between the shaft and block and force the crankshaft down into the space provided.
Using a screwdriver or similar tool, push the seal out of upper bearing so end can be grabbed with pilers and pulled out. Wiggle the crankshaft slightly to aid this operation.
Use the lower bearing cap to form the new upper seal into a semi-circle.
Insert a wire (soft tag-type) through the seal about 1/4 inch in from the end. Wrap the wire around the end of the seal so it has a good grip. Use a light coat of Vaseline to lubricate the seal and insert the wire into the seal groove and up and over the crankshaft. Pull the seal gently into position. You may need to rotate the crankshaft to get the seal placed.
With seal centered in the opening, cut off the ends so that they stick out 1/64 inch beyond the parting surface.
Install the lower seal in the groove and roll into place.
Cut the small portions of the ends which protrude from the groove flush with the surface of the bearing cap.
Install bearing cap over crankshaft onto the block.

NEOPRENE SEAL

Remove rear main bearing cap and pry old seal from groove.
Insert new seal with lubricant only on the lip. Do not get oil on the glue-treated parting line surfaces. Lip faces front of engine.
Using a hammer and small punch, persuade the upper half of the seal to revolve until it protrudes far enough to be removed with pliers.
Oil the seal except at the glue-treated ends, and using a hammer handle, roll the seal into place in the block. These seals are made to size and require no trimming.
Install the lower half over the crankshaft and replace onto the block.


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