Rear main leak part 4
 

After dropping the oil pan I removed the rear main bearing cap and this is what I found. There’s a shredded seal behind the cap that can’t be helping. Also, in the second picture the bearing cap there’s a couple of sleeves I didn’t expect. Is this all normal?

Re: Rear main leak part 4
 

Define "normal". Someone has converted the bottom end to insert bearing shells. They have removed the slinger and are using a rubber seal in its place.

Re: Rear main leak part 4
 

Thanks Brent. I’ve never seen insert bearings, so I wasn’t sure. Im guessing replacing the seal would help with the leak.

Re: Rear main leak part 4
 

Dale, yes replacing the seal will likely help stop your leak however you need to determine what caused the seal deterioration. Was the engine stored for a long time and then started with the seal rubber dry?

I cannot tell if that is a Terry Burtz one-piece seal, but if so you will need access to the entire rear flange of the crankshaft. Also, I would want to see how they are controlling the thrust of the crankshaft. That might have been a contributing factor for the seal failure. I do know that the craftsmanship on that engine seems very rough just judging by the reliefs that were "carved" in with a cut-off grinder for the insert shell tangs.


I will close by suggesting that you be cautious of the advice you are getting over on social media. You have everything from a former lawnmower mechanic to folks who don't even own a Model-A (-much less worked on one) giving you advice.

Re: Rear main leak part 4
 

Looks to me that the old, torn, seal is a rope seal as used in most engines starting in the late 30's, it is just graphite impregnated rope. I've used it many times, it works good but doesn't last like the Burtz seal.

Re: Rear main leak part 4
 

Brent,

Is this one of the inserted engines that uses the center main for thrust?

I believe H&H used the center main for thrust control with their insert conversion.

What I am seeing, I do not like the looks of.

It appears the rear seal was a molded seal of some sort and not just generic rope seal. This would definitely account for a big oil leak.

Chris W.

Re: Rear main leak part 4
 

I have rebuilt a grand total one one engine-mine and I don't like what they did there. The main cap has two 'half shells' that are not even letting oil get to the whole bearing surface. Maybe you can't I don't know. Just from pics I have seen of rear main bearings the inserts are one piece and not two.


My 2 cents.


Mike

Re: Rear main leak part 4
 

From the first picture , are the flywheel bolts a little long?
Good Luck Dan