Ford 800 rear main

[IM560]

Good morning. Need some input on replacing the rear main seal on a ford 841 gas. We have swapped it out about 5 times now and still leaking. first two seals were A and I, next one was thru case and the last one was a felpro. It seems like the seal is just hardly contacting the crankshaft but probably is more then it appears. the case fit a little tighter and the felpro better yet but it's still leaking. We've tried flush with the block seam and also clocking the seal away from the seam. Cam cover is dry, We put a fine film of rtv where the cap meets the block and the cap seals seem to be installing as they should. What else are you doing to make these hold. We are using the neoprene type C shaped seals not the rope ones
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[John0829]

Personally I prefer the rope seal, if done right they last for the life of the engine. I have seen to many of the neoprene leak when used in place of the old rope. Are you sure it is not the little wedges that fit on the sides of the rear main cap that are your leak?

 

[ruffdog]

Some videos:

 

[nyone]

I had a ford851 with a leaking rear main. I took the pan down once and tried to pull the top half out with no luck. Even got the tool to do it. Owned that tractor for about 10yrs and it became an add oil only machine. It was a 65yr old machine it can just mark its teratory.

It would get water in the transmission and a few winters i would go to move it to find that the trans wouldnt spin. It still survived and I sold it for what I bought it for 10yrs prior and many many hours on the clock later.