Hey guys, I've been having this grinding feeling/sound coming from somewhere under the truck. I can't exactly pinpoint where its at but it's defintiely somewhere in the driveline. I don't think its in the tranny, maybe farther down the line. It happens mostly when im running the truck at a low rpm, kinda like when your stuck behind somebody who thinks 35 is the new 55! But it goes away the second you either let off of the throttle, or get on it. It just seems to be getting worse everyday. Does anybody have any idea what it could be? Anything helps.

Thanks in advance, Shawn

 

Anyone... anyone....
My sister in laws durango did the same thing for a while but it just went away.

 

Does it have limited slip in the rear differential? You might need to change the differential fluid.

 

Check all your U-joints. I heard/felt a vibration wasnt real bad, but when I crawled under the trk the driveshaft u-joints were toast.

 

None of the u-joints have any play in them, I check 'em pretty regularly after I did the front ones seeing as they were toast. As for the diff, its a 9.25" "anti-spin differential", I'm assuming that to be a limited slip. But yeah, I changed the fluid just a few months ago. It's been grinding ever since I bought the truck, October before last, and it did go away for a little while but recently its just been getting worse and worse. When I changed the fluid, I did notice a small chip in the one of the gears, but if it was slipping that badly, I think I would see a lot more damage! I don't know, I might pull the cover this weekend and check again seeing how its not that expensive for three quarts of diff fluid, but I'm almost affraid of what I'll find! I really don't wanna shovel out 900 bucks for a new rear-end

 

Better now than getting stranded.
Also check the stone shield for the gas tank and the cat and muffler.

 

I checked the cat, it doesn't sound like theres anything loose when tapping, lightly, on it. I'm not too sure how I would check the muffler, and has as rocks in the stone sheild go, I doubt that would be it seeing as the noise stops the second you let off of the throttle, or get on it! Could it be the a bearing somewhere along the driveline or would that be just a constant grind? This only happens when your cruising along at alow rpm and going up a slow grade. I cant tell if the truck looses power when it happpens cause I immediately let off the throttle now without even thinking about it. Next time, maybe i'll ride it out and see if the truck looses power, or backpressure which would alleviate the driveline and gear me towards the exhaust system, possibly?

 

I had some bad grinding similar to what you're describing. Turned out to be bad pinion bearings which are fairly common with the Chrysley 9 1/4. I'd be getting that checked sooner rather than later...

 

Dont forget that there is a limited slip additive that is supposed to be added when you change your diff fluid.

 

What kind of labor is involved in checking/changing those bearings? I'm pretty mechanically sound untill we start talking about pulling apart the different gears, then I'm getting a little iffy! How could I check them, I don't really have the wallet to be taking to a shop every weekend trying to find this thing out?