Rear Differential

[ramchuck]

I have a 2017 2500 Limited diesel. It has been well cared for and all services have been performed. Currently has 93,000 miles, and has done minimal towing. My issue is when the transmission downshifts there is a "clunk" in the rear end. I put the transfer case in neutral and you can rotate the rear driveshaft and see the "slop" in the rear end. There is no other noise, the diff lube looked good, so what do you think needs done. Can the differential be re-shimmed, or simply is it worn out and need replaced?

Chuck

 

[Dean2]

You need to locate the source of the "Slop". I would start with the U Joints, and check them for play. Then the intermediate/center support, bushing/bearing if you have one of those.

Hopefully it is one of those two because after that it gets expensive. If the slop is in the actual differential or the transfer case, you are going to need to open it up and locate the cause, most everything can be rebuilt if you know what you are doing or have access to a good shop. Let us know how you make out.

 

[62Blazer]

The normal and correct setup allows a certain amount of backlash/slop in the rear axle. It's hard to know if what you have is too much or normal, but point being if you rotate the rear driveshaft there is some slop.

 

[Gr8bawana]

If the "clunk" is relatively new it's most likely your u-joint.

 

[CanuckRam1313]

At nearly 100K Miles.... the front/rear diff fluid should be changed as well as the transfer case fluid, too.

I would also consider doing a transmission fluid & filter change as well. Your transmission will thank you!

As others have also indicated, check the play in the u-joints as these may be suspect parts that are aging

If it still persists, then as stated above, opening the transfer case may be necessary, too.