2001 dakota- a rock in my (nonexistent) hubcap?
 

I have a quick question. At least I hope a quick one...

I picked up a 2001 dakota quad cab, automatic, AWD for super cheap. Its been great to me so far!

I started hauling some fairly heavy loads for some landscaping and I notice a clunking sound from under the truck now. It sounds like a rock in a hubcap. It happens only under acceleration from about 5 mph to 15 or so, and then it seems to die off. Its definitely the drivetrain since it doesn't happen when roll-accelerating downhill or in N.

I read a TSB that said it could be the right front axle shaft bearing but i swear it sounds like it must be coming from the rear. I've also deduced it could be the driveshaft u joint from some light internet reading. I was hoping maybe it could just be low differential fluid, too, but would that make that sound?

Is there a good way to test this? I don't want to try and fix what isn't broken, and i'm having a helluva time hearing where its coming from, even with someone else driving in circles around me.

Does your truck have rear disk brakes? If so, I can almost 100% guarantee that the sound your hearing is coming from your parking brake shoes. The pad liners have separated from the backing plates and are now just rattling around in there and at higher speeds they are just thrown out against the sides. If you do have rear disk brakes just pull the wheel, and disk off and have a look.

Thanks for the tip but I have drum brakes in the rear, unfortunately.

After digging around under the truck for awhile, I decided to crack open and clean the rear differential. That didn't fix the sound. I checked the driveshaft u joints and they seem solid, but i did notice about 1/4" space between the flange on the driveshaft and the transfer case/transmission housing. All around the flange the driveshaft has a shiny wear ring, so it looks like it butted all the way up into the transmission housing when i had a heavy load in there.

I heard that some dodge transmissions are very sensitive to the state of the ATF fluid additives- when they get worn down, even with a proper fluid level and no discoloration, the transmission can clunk a little. That may be the source of the sound so I guess I'll change the ATF fluid next.

A friend rode in front with me and had his head out the passenger side window. He said it sounded like it could be coming from the front passenger side wheel area. Its a bear to track down so far.