I have just started noticing a Grinding/Rubbing noise that seems to be coming from the front of my 98 durango 5.2 4x4. I only hear it right before the transmission shifts from 1st to 2nd and 2nd to 3rd. I was thinking it was coming from the transmission but it sounds like it is further up. But I also notice my trans slipping 2 times the other day, both when the truck was cold and had just been started and both times on a hill. Is it possible that there could be a problem with the lockup torque converter? Thanks

 

Now that I listen more carefully I think the noise could possibly be the rear end.... I have been reading the posts about the limited slip additive. If I put some of this in the rearend to see if thats a problem will it hurt my rearend if I do not need any in it? Or do I need to drain the whole rearend and refill? I would rather not have to do that.

 

If the fluid is good then don't replace. You would be the only one to answer that question.

Adding the Anti-friction Modifier (limited slip additive) to the rear end would be ok. It's not going to hurt. It is a limited slip.

Also, it could be a U-joint as well.

 

is there a way to check the ujoints?

thanks