Clunk in rear end cj5 dana 44

When I first go into gear or from forward to reverse, the rear end has a large clunk noise. What is likely to be the problem and how long can I run with it this way? It has plenty fluid and it is in the rear end, not the universal joint. I want to drive it about 3 thousand miles before I try to fix it if I can.

 

sounds like you have a powr-lok or a lot of slop in the diff to me.

what's the oil look like?

 

Check the pinon nut. It might be loose, mine was.

 

+1, just crawl under it and grab the pinion and see if you can move it. If the nut is tight then its your pinion bearings..

 

The pinion nut is tight, how long are the pinion bearings likely to hold? The oil looks new and clean, I changed it about 2000 miles ago.

 

Maybe someone who knows more about building differentials will correct me...

Is this axle noisy? Usually they will be really noisy for a long time before they break entirely. Due to extra runout, the pinion seal will also start to leak if the outer pinion bearing is failing.

The outer pinion bearing usually fails first because it is the first to suffer from low oil.

Are you sure this noise is coming from a lot of backlash? A clunk can also come from badly worn transfer case output shaft splines.

First thing I'd do is remove the rear driveshaft and drive around using the front wheels, making sure the noise comes from the rear axle, rear driveshaft or rear output.

 

I agree with Tim. I can't think of anything in a diff that would cause a clunk, and then run smooth. If it had wear in a shaft, bearings, too much lash, not enough lash , or a busted tooth, etc. Anything like that would cause running noise. Noises can be funny, and transmit from somewhere else.

 

What about springs and shackles? Worn out shackle bushings, or something broken? Any way you can get it up on a lift somewhere and do some poking, yanking and wiggling?

 

Checked your u-joints??

 

In neutral when I move the driveshaft by hand, I get the clunk and it is from inside the differential. When I move the jeep back and forth by hand with it in any gear, I see the whole rear end cam a little on the springs, and the noise comes out of the differential. The jeep has new springs, shocks, shackles etc....
How hard is a differential to rebuild? The rear end seems to do fine except for the clunk which happens when I shift from reverse to forward, or forward to reverse and sometimes when I let the clutch out after coasting. I want to drive up in the mountains of colorado and do not want to find myself stuck up there with a locked rear end. I guess I can get out with front wheel drive as long as nothing locks up.

 

Howdy, years ago I had a Barracuda that clunked like you describe. Turned out the spider gear shaft had worn a slot in the carrier. The ring gear kept the shaft captured and once you were in gear and going, it did not make any untoward noises. Fixed it for the short term by moving it all the way to one end of the slot and arc welding lug nuts in the oval holes that remained. I did not weld up the spiders or over heat the carrier and it functioned as a normal differential for some time afterwards. I would pull the cover and check. Stinky, messy job that is best done at home. Did you say what gear ratio, spline count and if Limited Slip is it a Power-loc or a Trac-loc?

 

This is a dana44 with the 5.38 gear ratio and tapered axles. It has new wheel bearings and seals. I guess I am going to have to go inside and see what is going on. Are parts hard to come by?

 

I had the same problem. I was all worried about swapping rear ends. It ended up being the ujoint. And I had checked it previously and ruled it out. I was amazed. Maybe put the t case in neutral and try it again?