Chatter in my drive train

[Gene]

I'm starting a new thread on this issue since I have more details. I removed the rear tire for new rubber and brakes on my 2000 Interstate. I inspected the driveshaft and cleaned up the final drive unit (did not open it) and reassembled to find an intermittent gear chatter when shifting and deaccelerating. I put it back on the stand and pulled the final drive and shaft. I changed the washer, snap ring, spring and oil seal on the drive shaft, even though they looked fine. Reassembled smoothly with only a little trouble getting the driveshaft to reengage with the u joint. hand tightened the final drive unit, installed the wheel, brake, left spacer and axel and tested it out. Same issue!? Gear chatter between gears and deacceleration.

Somebody help me out here, I'm trying not to take it to the shop and don't like running it on the road with this issue. Any ideas?

[Chrisj CMA]

Did you then torque the final drive nuts after torquing the axle nut?

Added:

Final drive alignment and torque settings on the axle and final drive are critical. The wheel must be unsupported and off the ground and the final drive able to move when torquing the axle nut.

[HayHauler]

Are you missing the Teflon spacer that goes between the wheel and the final drive?  That will cause the final drive to rub on the wheel and could cause the noise you describe.

It is a Teflon spacer about 2.5" in diameter that fits in the back side of the driven flange.  I can't seem to find it in the parts fiche, but I have a new one at home.

Hay 
Jimmyt

[Gene]

I loosely hand tightened the final drive nuts before putting the axel in. The tire was lifted off of the ground. Then I torqued the final drive nuts. I'm not sure about the teflon spacer, I replaced the oil seal on the driveshaft. The wheel has an O ring around the final gear on the wheel. I didn't notice a teflon spacer, but I'll recheck the manual.

I suspect it is either the shaft to U-joint connection, or maybe, but less likely the shaft to the final gear box. I checked to make sure the shaft was snapped into the gear box before installing, although it makes it much harder to check the front driveshaft and U-joint connection.

Does anyone install the driveshaft first, and then attach the final drive box? The manual doesn't recommend it, but how else can you assure the splines are aligned at the u-joint?

[Chrisj CMA]

Install the final drive and drive shaft together. If it goes in the uJoint spines are good. You can't get that part wrong. The nylon thrust washer mentioned goes under the flange and lays directly on the wheel hub and right side wheel bearing.

It sounds like to me the issue is likely a bad U-Joint. Sorry to say you have to take everything apart again to get the U-joint out. However, you do not have to remove the swing arm

[HayHauler]

I believe the "thrust washer" I am talking about is #5 in this fiche, but I am not positive.  The image shows it thicker than it really is, but I think that is it.  It fits up inside the back side of the flange.

https://www.ronayers.com/oemparts/a/hon/506cb694f870023420a418c9/rear-wheel

Hay 
Jimmyt