JD350C Final Drive Backlash

[Tjgerow]

I have new bearings, races and seals in the final drives. I assembled per the manual, I hope.

I was able to get the axle preload/backlash of 0.001 to 0.005 with about 1/2 of a turn of the axle nut once it made contact with the washer and inner bearing. I turned the axle clockwise and counter clockwise at least 6 times each and then checked the backlash again.

This is my first time putting a final drive together and that just seemed like very little movement of the nut to get to the tolerance specified in the manual. Does this seem correct?

The bull gear has about 0.080" of side to side play. Its basically floating on the axle between the two spacers. The inner spacer (p/n T59766) was missing on both final drives when I took them apart.

The bull gear also has about 0.030" of rotational play. i.e., the bull gear can move 0.030" before the axle starts to move. I didn't see any specifications for this in the books. How much wear on the axle splines or bull gear splines is normal?

If I rock the axle flange back and forth the bull gear starts to "ring" pretty good due to that 0.030" slop.

One last piece of data, it takes 107in-lbs of torque to turn the assembly. There's no pinion installed yet, so thats just the axle assembly. This seems to be in spec for new bearings, and this is with the nearest hole lined up for the cotter pin. I had to advance the nut (tighten) a bit to line the hole up for the cotter pin.

[LeonardL]

You should be okay with your final drive. They're not an exact science but still need to be pretty close. It sounds like you have achieved what you need. Those retaining nuts are pretty course threaded so it won't take much of a turn to mean quite a lot on adjustment. Back lash noise in one of these finals means very little. It's not like you're going to drive this thing at highway speeds. I think a 350 runs about seven or eight miles an hour and that's on a good day going down hill.