Rear-end Thunk Noise?

[Delonybro]

I've searched the forums extensively and can't find anyone with this same problem.

I drive a 2000 XLS 2WD with 105k miles and spend a lot of my time driving at night catching rattlesnakes for a research group (yes, I'm weird), and often I drive past the snake, have to stop, reverse, and then catch them. On that reverse, there's often a loud "thunk" coming from what feels like the rear end, much farther back feeling than just the transmission. After I put the car in reverse, I push the gas and it'll go "thunk" and then back up, sometimes with a slight groan. Any ideas? This doesn't happen going forward, or if I reverse out of a parking spot, only If I've been driving forward for sometime, stop and then reverse. It's driving me nuts! Thanks for any ideas!

 

[my pos mounty]

First, do yourself a favor and make double sure your truck is at a full stop before dropping it in reverse. You will save yourself a ton of cash later on down the road.

If your lucky, that noise is just a u-joint. Replace it and the noise should stop, if you are unlucky you could be looking at a pinion bearing on its way out.


Do you get that "clunk" or a shudder when accelerating from a stop with the wheels turned in either way?

 

[Delonybro]

Do you get that "clunk" or a shudder when accelerating from a stop with the wheels turned in either way?

Come to think of it, yes, the wheel is often tuned when I hear the noise. Again, it only happens when I'm in reverse, never going forward. I'll check out the u-joints today and see of there's any play on the drive shaft.