ratboy3124

I just came back from a trip to OK and back pulling an empty 4 horse up and loaded back. Now when I back up I can hear what sounds like a hollow thumping coming from the rear end. Any ideas as of what it could be? I am praying it isn't my rear end getting ready to go out.

ProspectorTim

Check the cheap/easy stuff first.
Have you looked at the plastic inner-fenders lately?

Those Oklahoma roads can loosen up the plastic fasteners, and the inner fenders can make more noises than a Mocking Bird!

hotdram

Is the spare tire secured tightly? They come loose over time.

~Rob

RustyJC

Is it 1 "thump" per wheel revolution? If so, check the tires for bubbles, lumps, etc. as it could be the start of a tread separation.

Rusty

hotdram

Another "thought". Do you have the limited slip differential? Do you have the friction modifier in it? Could be the clutch plates chattering (mine sounded a bit like a thump when I didn't have the stuff in).

~Rob

ratboy3124

Checked everything and everything seems good. I noticed it does it when I am turning. When I have the wheel turned to the right in drive and reverse. Doesn't seem to do it any other time. Yes I have the limited slip.

Tiger Rag

My rear end knocking vibration was the carrier bearing on the 2 piece drive shaft had failed and come out of the carrier. Check it if you have a long bed. They are prone to fail after 100k miles.