Hey guys. I'm desperate for ideas.. I have an 01 Grand Cherokee with the 4.0 selec track. I'm getting this grinding noice sounds like from under my seat. It gets worse upon acceleration. I've changed both CV shafts/front axels. New brakes new wheel hubs, new u joint for front shaft new shocks new pitman arm and drag link and receiver. I dont know what to do. I just changed the saftey neutral switch on my transmission and now the grinding. Any ideas? Shifts in and out of 4 wheel part time and full time and low no problem. Part time light just quit working though

 

That's never a happy sound.

Can you get it up on jack stands and do some listening? A mechanic's stethoscope is an amazing (and cheap) tool that will tell you a LOT in a very short time. Everybody should have one. Poke it against the suspect part and just listen. You'll be amazed what it will tell you.

Put it up, run the engine and put it in gear. (Obviously, you have to be sure it's stable on the jack stands before you do this!) Poke the stethoscope against everything that might possibly cause noise while moving. I think you''ll be able to find your problem child.

 

I jacked up the rear end and put it in drive my driver side wheel started squeaking mildly and at the same time had a bit of a wobble to it I couldn't hear the same grinding noise that I was hearing while driving but I took the rear wheel off I cleaned it up playing the road are playing the break everything like that and it hasn't stopped but it got a lot better And also while I was driving I was running about 55 mile an hour and I put it in neutral the noise still continued whether the transmission was engaged in drive or not I don't know but does that mean I have been rule out the transmission anyway I'm gonna check the rear end U joints this evening and change them if possible I already changed the front shaft By the way I noticed that ever since that started the grinding noise my part time 4 wheel drive lite will not come on and the grinding noise has turned into more of A loud roar But if I hit the gas hard enough from a stop it sounds like gears grinding

 

I Will try the stethoscope this evening

 

Just a guess... When my T-case linkage got worn it made all kinds of weird noises and its just uder the driver's feet.

 

Just a question But would only do it while I was Four wheeldrive

 

Punctuation is free. Use it. You aren't texting wit your buds. You are asking people do GIVE you their time and expertise for FREE. The least you can do is to make the effort to make your posts readable.

 

Did you ever figure out your problem? I have a similar problem. 1999 Grand Cherokee Limited. When I got my Jeep it had a whining rear end and it would kind of grind to a stop. I bought a Craigslist rearend for $150, his 4.7 had overheated and seized. I swapped out rearends and the howl was gone, but then I could hear the scraping sound was still there. I thought they were the same problem. The previous owner had removed the front driveshaft, replaced brakes and put on new tires. I removed the emergency brakes, could be dragging. Didnt help. I had put new axle bearings in my old rearend so I put these axles in the new rearend but same scraping noise. I'm at a loss, I cant think of any more causes, I checked the backing plates and they are not rubbing. I don't really hear it when its on jack stands.....any more ideas?

 

How about rear u-joints?

 

Could be bad bearings in the transfer case if it only does it in 4wd.