You won't like the answer.
The outer bearing is a press fit in the case cover and is retained by a dowel pin. The cover will have to be removed to get access.

ahhh, ok....its not good news then......are either of these bearings more prone to failing that the other?

Hard to say....what are the reasons why your currently in there???

"Old wrote:

Hard to say....what are the reasons why your currently in there???

As yet I'm not in there, but I have a couple chipped teeth on the inside (chassis side) edge of a bull-gear and was wondering if these bearings were the culprits or whether it was the inside bull-gear bearing.....really don't fancy the possibility of a strip down

Pull the drain pluges on the final drives to see what kind of metal comes out of them ! You may find the pinion gear teeh there!

"rjh-md" wrote:

Pull the drain pluges on the final drives to see what kind of metal comes out of them ! You may find the pinion gear teeh there!

only found two pieces and they came from here

Can't make out the overall wear pattern but end breaks on the teeth like that are usually a result of not keeping the outer sprocket shaft bearings adjusted which allows the bull gear to cock, along with shock loading.

Richard-J-W I would be taking a good look at your bearings. What kind of material have you been getting in your magnetic screens in the service intervals prior to this failure?

When the Cat final gears come apart due to wear you first will see the edges of the gears producing an edge you can shave with long before large pieces start breaking off just one spot. You would also have flakes of metal in the service intervals prior to this type of failure.

When the final gears are broken from shock loading you would see a few gears broken in succession like yours, but they will be broken clean across not just on the edges.

The gears look something got wedged into the side of them or another possibility as Old Magnet pointed out misalignment caused by the bearings.

This in an 84J?
The 84JSa's are known for bearing failure in the finals when running a large amount of continuous horsepower through the tractor causing heating of the gear oils that break down the lubrication resulting in premature bearing failure. If the bearing failure is not caught in time you wipe out the bull gear.

Do you still have the broken pieces?? There's a good chance you can tell if they were forced off by something jamming the gears or a clean pressure fracture.

this is all that came out of it





Its an early model, 88A.....which I think was 78A in USA (how many 'A's is that? ) and it has 22" pads which I am thinking will put a higher than normal load on the final drives

The bearing adjustment you talk of is this big nut which needs what seems like a hook-spanner on a 6ft pole, yes?