You do have a final drive problem,and should be pulled down ,but even with the amount of chiped teeth on bull grear, its not you orginal problem ,unless the uppr pinion gear teeth are destroyed .I am wondering if the pinion flange is lose on the tapered splines on the pinion shaft or posibly a broken pinion shaft .Since you have the steering clutches out of the tractor ,I would susject pulling the entire upper pinion out of the main case ,starting to see if the nut retaining the flange is lose ,and workin in ,removing the cage retaining bolts and remove the cage and pinion from inside the main case to get a good look at the pinion ,and bearings

Those are great pictures.....
Yes on the bearing adjustment nut.

I do not see the typical gouging of the broken teeth that would indicate that something went through them (metal)

I do see the effect of misaligment wear on the edge of that one tooth quite clearly and the typical fretting resulting from lateral movement of meshing teeth.

With the bull gear cocked, loading becomes very concentrated on the outer edges of the gear teeth. Sufficient loading, uniform and shock will break pieces off in that fashion. Except for that failure the tooth wear does not appear to be all that bad.

Were there any other unusual symptoms to operating.....like a pulsing brake pedal that would indicate pinion bearing problems?

Looks like your headed for a tear down to me. The pinion will show affects of running in that mode, even if bearing adjustment has currently been corrected. Still warrents investigation.

The script on page 1 was asking about why his tractor did not turn port and starboard with any great speed, the answer is simple, no brake effort, the fact that things worked better in reverse is due to the brake band wrap effect,to repair it I would have fitted new break linings, the inner hubs with markings is simply fixed by swapping them to the other end of the cross shaft, so in effect reversing the wear area.

Richard your bull gear dropping off a few chunks realy means the big strip out, as those top pinions would have taken a fair shot on the chin, although they spin at the speed of light compaired to the bull gear they also have the most wear due to the amount of work they are doing, best get your spanners out and make yourself an all day sandwich???

tctractors

p.s. the steering clutches need to be swapped complete on the cross shaft is the best thing.

Hi Richard, I can only agree with TC when I see a ring gear in that state, strip down the complete final drive, you have to take the cross shaft out to change the pinion bearings, so unless you find a good reason not to, change the pinion bearings on the other side while you are at it.

Cat had the Bull gear tooth shape cut in such a way (Crown Shaven) to cope with an amount of bearing discomfort, the brake drum also changed from a 10 bolt to 14 bolt fixing on D4-951, if the cross shaft is removed on any Cat its worth doing both top pinion inner bearings and seals.

OK, I am convinced......full strip-down looks imminent