Farmall Cub

Hello-

I am in the process of an engine overhaul on my 1950 Cub. A few of the connecting rod bearings have light scratches - just one strait scratch across the bearing surface. The crank is clean, no scratches, and measures within factory specs. Should I replace the bearings or re-use the original?

Thanks for the help,

Matt
NJ

I have a 1947 Cub and it sounds like we are doing about the same thing. When I checked the inserts they had a minor scratch in the center but the crank bearing surface appeared good and measured within tolerance. I talked to several people and got various opinons. Someone suggested that when you have gone that far why take the chance. That made sense to me. I decided to replace the bearing inserts

I have them on order.

Bob

I agree with Bob you are that far in just as well do them and know that you wont have to worry about them later.

I'm defenently not the person to say for sure, but I've seen the same thing in other engines so I'm thinkin its fairly common to see a groove or scratch in a bearing were something like grit got pumped through. I don't think it will hurt a thing and might help lube the journal better anyway.

If you intend to work it, I would replace them, there is always metla fatigue to consider. if it is only for show and occasioanl parades they will probably be alright.

Thanks for all the input. It does indeed make good sense to replace them at this point. Certainly much easier now than later. Will order them in the morning.

Thanks again,

Matt

These are precision-insert bearings. A bearing protects itself by letting particles actually embed in the bearing lining material. It's called embedability.If the material was to hard to allow this it would lie on the surface and scratch the shaft journal. Now if to many particles (embed) on the bearings.That would also result in failure. To big a particle and that too.With oil filter, air cleaners, screens ,particles of dirt will get in engine. Cub engine ,what cranks @1800 rpm The bearing load is on the connecting rods are not that great. Combustion pressure around 100psi . What do you think? How deep is the scratch? If it was my call .A Little 600 paper on the scratch and lock and load.

With all the work already expended it's a $40 bet

Bob