Rear Main Seal Leak

tony1963

Well-known member
I did a total rebuild on my 200 and the engine runs great. Even after flat top pistons, not much power, though. Oh well.

The only problem is the rear main seal. It has the rope style and does leave spots on the driveway. What is the correct method of installing this thing to keep it from leaking? If I'm going to pull the motor back out and do it again, I'd like some advice.
 
I would check to see if you could find a neoprene seal like that is used in the later models, is a much better, lower drag, and longer lasting seal. Other than that you have to fit a rope seal properly seating it into the grove all the way I use some round bar stock that is about the size of the crank main and tap it snug than take a single edge razor blade and trim to the block.
 
Did a search. Try this. Yes & it does work.Scrap the rope seal it is antiquated, Falcon Man
Report this postReply with quoteRe: Rear main seal advice?
by wsa111 on Sat May 23, 2009 7:56 pm

This is from a previous post, & it seals to perfection. Bill

Hope this helps, install the rear main seal with the ends at 10:00 o'clock on one side & 4:00 o'clock on the other side. Then put a small daub of sealer which you need to purchase at a toyota or lexus dealership. Its called FIPG.Permatex ultra gray sealer is also good. Put a small daub at the butting surfaces of the neoprene rear main oil seal. Before you put the rear main bearing cap in place place a very small bead of this sealer at the outer edge or lip where the rear main bearing cap contacts the block. Also place a very small bead from the seal to the outer edge where the main cap sits to the outer edge or where the cap contacts the block. Don't forget to place sealer on the flywheel or flexplate bolts to the crankshaft.
Using this procedure i have never had a rear main oil seal leak or even seep. This applies to fords & chevrolets, big block or small block with the 2 piece rear main seals. Bill67 mustang,C-4, with mod. 80 log head, custom 500 cfm carb with annular boosters, hooker headers, dual exhaust with X pipe, flowmaster mufflers, duraspark II distributor with MSD-6AL. Engine 205" camshaft inovations cam & 1.65 roller rockers.
 
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