New noise with new rear axle

jgdisco2

Well-known member
Feb 24, 2006
769
1
Goldsboro, NC
Blew the axle up at URE last Oct and this week finally got the replacement axle installed as well as made the conversion to a 4 bolt flange from rotoflex. Here's where the problems began. Everything is secure, no play in the driveshaft, fresh diff oil(75w-90). When I accelerate and am on the gas pedal, things seem normal. When I let off the throttle, I begin to get a gear/bearing type noise until it slows to about 25 mph then it goes silent again. I have checked the U-joints on the driveshaft, they seem good. Again no play at the new flange. I'm lost as to what this could be, my only guess is perhaps a wheel bearing or something in the gears.
 

squirt

Well-known member
Nov 13, 2008
797
2
Los Angeles
Yep, check ring/pinion backlash. Pinion bearing may also be the issue, though I suspect you did a cursory inspection before installing the new axle.
 

jgdisco2

Well-known member
Feb 24, 2006
769
1
Goldsboro, NC
So follow up to this, still had the noise following the front diff swap as well. Went ahead and pulled the new rear out and found this. I believe I caused this when I changed the flange so I could run a non rotoflex shaft and did not realize I needed the spacer since it wasn’t in the kit. I put about a mile at low speed in the neighborhood before stopping. 56365Would that cause the chipped teeth on the edge of the ring gear?
 

ezzzzzzz

Well-known member
Apr 22, 2010
575
2
SE Va
Without the spacer the pinion bearings aren't properly loaded. The pinion was likely walking away from the ring. The load would be concentrated on the tips of the ring gear. The excess load would cause this damage.
 

jgdisco2

Well-known member
Feb 24, 2006
769
1
Goldsboro, NC
I’m pretty sure that’s exactly what happened even though it was only a short bit and low speed. New diff from Will T and problem solved