Bad sound coming from Jeep.

[gbelous]

I have a 2003 Jeep Liberty Sport 4x4 with about 123k miles. My wife noticed this yesterday. When he was coming to a stop or slowing down by taking her foot off the gas, there would be a random clunking/clicking sound coming from what I can tell is the rear. Kind of like something was stuttering or grinding. It happened very randomly and usually at lower speeds like doing circles in a parking lot.

On the way to the mechanic, I was on the highway and it was all quiet until a couple miles in a really loud rapid clunk occurred for 3 seconds then went away. Kind of like someone sticking a piece of wood in a fan. A couple miles later it happened again. I wasn't accelerating hard or breaking, just driving about 50mph.

The mechanic test drove it twice today and didn't hear any noises. So I don't know what to do. I don't want to drive it in fear of making something worse, but how can he troubleshoot if there are no noises?

Has anyone experienced this? Any suggestions?
Thanks for any help!!

 

[tommudd]

Does it have the trash loc in the rear?
Sort of sounds like it maybe sticking from not changing fluid or just worn out

 

[gbelous]

Not sure what it has. Is there any way to tell other than taking the differential cover off...if the mechanic still can't get it to make any noise? I've never changed the fluid or put any in, so I have no idea how old/worn it might be.

 

[tommudd]

Well if you have never changed it thats where I would start
pull the cover and see what it looks like inside
Its way past due anyways
Also check the rear brakes to see how worn and the emergency brakes as well

 

[gbelous]

Yeah, I will have to do that soon.
The mechanic just called and said the e-brake pads are falling apart and that's what was getting stuck and causing the axle to make the noise. Of course while he was in there he saw that the brake pads are really low and there was a cross-threaded wheel stud (that I did years ago), so in the end, 400 for everything.
Thanks for the help and yeah, I will have to replace the fluid soon just so we make sure nothing else happens.

Do these differentials need the friction modifier? I have a 01 Grand Cherokee that needs it, so just curious.