I slide into a curb when it was icy the other day and I bent my rear axel shaft so I replaced it but when I’m in reverse ONLY there is a knocking/clanking sound coming from the wheel that I replaced the axel shaft on. I also had to replaced the rim and did the brakes, rotors and wheel bearings. I run out of options on what it could be. When I lifted it the sound is coming from the wheel area not the diff or anywhere else. The axel shaft and rim was from the pull yard by the way. Anyone have any clue what It could be?
You might have bent the axle housing itself. You might have damaged the differential carrier bearings or the carrier itself.
Put the car on a level surface, check that surface WITH a level. Check to see if the side you replaced is vertical. I.e. the camber angle of that tire is close to zero. Solid axle cars will have a bit of negative camber (tilted in at the top of the tire) - about -0.3 degrees to as much as -0.75 degrees but it should be similar side to side. If the side you hit is greater than the other, I’d say the housing is bent. That may set up a chatter you feel only in reverse but likely it will tear up the axle bearings you just installed.
If camber doesn’t show anything, it is time to open up the axle cover again and pull the axle shaft you installed for internal inspection.
Is the junkyard axle very smooth on the bearing surface? And I mean perfectly smooth - polished! The shaft must be smooth on the bearing surface or it will cause chatter and eventually destroy the bearing.
Check the differential carrier and bearings for roughness. Post back with what you find, please.
Check to Make sure the wheel isn’t wobbling side to side as it rotates. Usually done w/ a dial indicator gadget on the hub, but can be done by eye if you can rig up a way to point the tip of a nail at it, and watch to see if the gap changes when you rotate the axle.
Concur with the post above too, if you have a solid rear axle configuration (like my own truck has), perhaps the angle of the axle shaft is no longer 90 degrees to where the roller bearing seats. Caused by a bent solid axle or something inside the differential.
Usually I’d guess that problem to be caused by the differential side bearing not meshing w/the axle shaft splines any more, b/c the side bearing or its grooves (for the splines) are damaged. Noises can travel along the axle shaft possibly and seem to be coming from the wheel area when the source is at the other end.
can you jack up rear end and spin wheels in reverse and than forward to verify the sound comes and goes? does jeep have rear drums?
Any chance the clanking noise is echoing through the shaft? I was wondering about damaged spider or pinion gear.
Many moons ago I was along on a boy scout troop trip from Colorado to Yellowstone and the station wagon I was riding in developed a symptom very similar to what the OP has. The owner of the car kndew somehow what the problem was and stopped at a gas station – in those days gas stations had a repair service – and I watched as they pulled the axle shaft out and touched up the splines at the differential end of the shaft. That fixed the noise problem straight away. I guess the axle shaft splines on the differential end had gotten mangled a little.