Rear end clunk

[beavis195]

Two days ago a noise started that is really starting to make me mad. Everytime I go over a bump there is this clunk. It sounds like it is coming from the rear somewhere. At first I thought it was my trailer ball still in. Nope. So I get underneath the car and I check that my new shocks were installed right. Well one end of the swaybar was not cranked down, so I cranked it down. Didn't solve the problem. It can't be my trailer hitch because I just discovered it is welded to the vehicles frame! It couldn't be the shocks because that was almost a month ago I got new ones. Anyone know what it is. Thanks.

 

[Robert]

Check your rear wheel bearings. Mine had a bad clunk coming from the rear on very small bumps. Lift up a rear tire, with your hands on the top and bottom of the tire push in on the top and pull out on the bottom. Reverse directions. If you can move it at all they are bad. Mine moved such a small amount I didn't think mine were bad. I had a repair shop look at it and they said they were bad. The noise hasn't been back since I had both sides replaced.

 

[Rhett]

Also check your u-joints on the driveshaft. If the u-joints are going bad, it can cause the clunk you describe. Ford u-joints tend to clunk for a long time before they finally go out. To test, get under your truck, and take the driveshaft in your hands, and try to move it around. It shouldn't move much.

Another possibility is that your spare tire is not tightly fitting up in there and is bumping something. Same goes for the exhaust pipe. Check the hangers, and check the heat shields etc. But I suspect it's your driveshaft. Not a big deal, pretty common for them to go out once you get some miles on the truck. If you find the u-joints are indeed going out, when you replace them, make sure to get GREASEABLE u-joints. Some have built in zerk fittings so you can easily lubricate the u-joints.