I have a 2000 4wd np242 Chrysler 8.25
dana 30. I swapped In a 1997 Dana 30 off an other XJ and ever since I’ve been getting a bad knocking even going over bumps and such. When I swapped the axle in I also just used the calipers and rotors off my 2000 axle. Could this be the cause of the knock? I’ve tried a lot of other stuff to stop it and nothing helps. The knock goes away in 4wd. And when I’m rolling backwards like off my driveway and I tape the brake pedal it will make the noise the worst. Should I try getting calipers and rotors for a 97 and put them on this axle?

 

Have you looked at the brakes ? if they are knocking you should be able to see the problem

 

The bearing hubs need to match the rotors. 2000 and 1997 are different, see this thread for the year splits.
https://www.cherokeeforum.com/f67/qu...38/#post191005

That shouldn't cause knocking though. I'd look at the control arms, track bar, sway bar etc and see if they are intact and not sloppy. You might have missed torquing something down. Also note that you should do the final torque with the weight on the axle, not hanging at full droop.

 

[QUOTE=DOBBSE.;3670407Should I try getting calipers and rotors for a 97 and put them on this axle?[/QUOTE]

lawsoncl is right on. You can keep your calipers but do get some 97 rotors. As for the hubs, you'll need 97 hubs. That much needs to be fixed for sure. Do that and then see if you still get knocking. While you are at it, check the condition of the axle u-joints and make sure there are no loose caps.

 

I'd definitely be checking out the u joints up front. Axle yoke and at either wheel end to start. If they are pre-existing u-joints that you didn't change with your axle swap - and they aren't greasable - look for fine rusty powder around the seal of the u joint caps. If you see the fine rusty powder you might as well plan on changing them out because at best at that point they are dried out and should be replaced anyways.

Overall nut and bolt check would be another route to start. Control arms upper and lower, I'd argue if your track bar was lose - you'd definitely know about it thanks to death wobble.

Did you re-use hardware for your shocks? check those as well - if your upper shock mounts aren't tight enough they can be sloppy or make a little noise. The bushing up there should be compressed enough to reach the outer diameter of the bushing "caps" and thats both top and bottom so from the inside of the engine bay as well as inside the wheel well.