Which brand ROPE Rear Main Seal?

I have spent more time trying to get the rear main to stop leaking on this tractor (1955 FORD 640) than I have in rebuilding the rest of the tractor. When I tore it apart it had a rope seal in it. I have tried the Fel-Pro and Victor seals.

None of the neoprene seals seat in the block. They will seal in the cap but not the block. The seals leave a gap between the block and the seal mating surface. They fit the crankshaft fine, but do not seal in the block. I have no problem getting the cap side packing sealed and have no leaks at the cap/ block interface.

On my last attempt I made an aluminum shim to place in the block to take up the extra space between the neoprene seal and the block surface and used the Victor Bead n Seal to seal the crankshaft seal in place. I used HOBO s trick of air pressure and soap solution to check for leaks. NO leaks. Drove the tractor around the fields for an hour and a half and now I have a rear main seal leak.

I stopped at a nearby New Holland Dealer and talked to the old timer mechanics working there. They said they had seen several neoprene seal failures as they were not designed for these old tractors and to go back with the rope seal.

OK. Now back to the original question. Which rope seal do I use? I can get one from YT which is probably a Tisco or other. I can order one from New Holland or I can get a Best Gasket (located in California) and get their Graph-Tite rope seal. Which one would be best, as I have it in me to redo this rear main just one more time.

If it were me I would go with NH if I
couldn't get a fel pro locally.

Don't have a clue what you have done or
checked but it's been my experience that
rear seal leaks are almost always the
result of the main bearings being worn.
Every brand is the same in this regard.

Whut M-MAN said...

What about excessive crankcase pressure that will nullify all attempts to seal a engine...

In your case I doubt a rope seal will fix it I hope the best for ya but when all fails the crank needs to come out to find the issue and repair it...

The last fel-pro rope seal set I picked up I did not like the fit so used what came in the tisco set...

Try best gasket there rope seal material is the best out there.

(quoted from post at 10:02:04 07/18/19)
Whut M-MAN said...

What about excessive crankcase pressure that will nullify all attempts to seal a engine...

In your case I doubt a rope seal will fix it I hope the best for ya but when all fails the crank needs to come out to find the issue and repair it...

The last fel-pro rope seal set I picked up I did not like the fit so used what came in the tisco set...

Click to expand...

Hobo, this is the guy whose flinger is broken off from his crank and he is trying to put the seal in the groove that is for the slinger and not for the seal. He will have to learn by trying the rope seal. The rope seal will get lost in that slinger groove. and will be worse than the neoprene seal.

I have never seen a Ford engine with a rope rear seal in any machine that didn't leak from the rear main. When I serviced irrigation engines. The guys with Ford engines would catch the oil from the rear main in a bucket and pour it back in dirt bugs and all.

OK forgot about dat...

Hey showcrop I might be dumb but I am not stupid.

I am NOT trying to put the seal in the slinger groove. I searched everywhere for the infamous slinger on the 640 Ford you have mentioned. It is not in any parts book, New Holland doesn't show a crank with one, and could not find one on the old interweb in any type of photo. I do not think they ever had one. If someone can find one point me to the web link.