Lets play the name that noise game
Thread Starter
Senior Member
Joined: Feb 2011
Posts: 897
Likes: 2
From: NJ
Year: 2004 WJ, 1998 XJ
Model: Grand Cherokee(WJ)
Engine: 4.7 HO
So since I was completely sure the noise was coming from the rear, I changed my differential fluid. It started raining, so I didn't take the cover off, just changed it. The fluid was black, almost had a grey tint to it.
I inspected the rear brake drums and everything looked fine on both sides. Rotated the tires while I was at it.
I checked the transmission fluid after reversing to go on a test drive from the differential fluid change. I went in reverse, stopped and continued in reverse and my transmission slipped pretty good. I checked the fluid after the test drive to warm it up, and it was pretty low and dark in color. No leaks from what I could see. I did the drain and fill a couple of times. Total of about a gallon and a half. Went for a test drive and no change.
I didn't get to the right front axle u joint because the rain came in, but I honestly don't think that is it, but it does need replacing. Back at square one. Any other thoughts? Anything in the driveshaft that would make that noise? The u joints seemed ok, with no play.
I inspected the rear brake drums and everything looked fine on both sides. Rotated the tires while I was at it.
I checked the transmission fluid after reversing to go on a test drive from the differential fluid change. I went in reverse, stopped and continued in reverse and my transmission slipped pretty good. I checked the fluid after the test drive to warm it up, and it was pretty low and dark in color. No leaks from what I could see. I did the drain and fill a couple of times. Total of about a gallon and a half. Went for a test drive and no change.
I didn't get to the right front axle u joint because the rain came in, but I honestly don't think that is it, but it does need replacing. Back at square one. Any other thoughts? Anything in the driveshaft that would make that noise? The u joints seemed ok, with no play.
Thread Starter
Senior Member
Joined: Feb 2011
Posts: 897
Likes: 2
From: NJ
Year: 2004 WJ, 1998 XJ
Model: Grand Cherokee(WJ)
Engine: 4.7 HO
So would a bad drive shaft support bearing cause this? Just started to get a vibration/knock under my feet at 60 mph+. This is a new symptom.
CF Veteran

Joined: Apr 2012
Posts: 1,843
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From: Ross Vegas, Ga
Year: 2000
Model: Cherokee
Engine: 4.0 w/ tupy head
to check drive shaft noise you would remove the front and test drive and then the rear do the same..and for that u-joint you don't have to remove the 36m axle nut remove the hub bearing and axle as one unit. Especially if you don't have a torque wrench cause you can damage the hub by over tightening it when reassembling it.
Thread Starter
Senior Member
Joined: Feb 2011
Posts: 897
Likes: 2
From: NJ
Year: 2004 WJ, 1998 XJ
Model: Grand Cherokee(WJ)
Engine: 4.7 HO
to check drive shaft noise you would remove the front and test drive and then the rear do the same..and for that u-joint you don't have to remove the 36m axle nut remove the hub bearing and axle as one unit. Especially if you don't have a torque wrench cause you can damage the hub by over tightening it when reassembling it.
Thread Starter
Senior Member
Joined: Feb 2011
Posts: 897
Likes: 2
From: NJ
Year: 2004 WJ, 1998 XJ
Model: Grand Cherokee(WJ)
Engine: 4.7 HO
Thought I felt a little play in the front u joint of the rear drive shaft. Went ahead and replaced both u joints in the rear drive shaft. No change. Still getting a rear drive train noise at all speeds. Pitch changes with speed.
CF Veteran
Joined: Aug 2011
Posts: 10,489
Likes: 24
From: Nor-Cal Coast
Year: 90,84
Model: Cherokee
Engine: 4.0,2.5
Thread Starter
Senior Member
Joined: Feb 2011
Posts: 897
Likes: 2
From: NJ
Year: 2004 WJ, 1998 XJ
Model: Grand Cherokee(WJ)
Engine: 4.7 HO
Thread Starter
Senior Member
Joined: Feb 2011
Posts: 897
Likes: 2
From: NJ
Year: 2004 WJ, 1998 XJ
Model: Grand Cherokee(WJ)
Engine: 4.7 HO
I usually fix all of my own stuff but I may take this to a mechanic to try and diagnose what's going on.
CF Veteran
Joined: Aug 2011
Posts: 10,489
Likes: 24
From: Nor-Cal Coast
Year: 90,84
Model: Cherokee
Engine: 4.0,2.5
Thread Starter
Senior Member
Joined: Feb 2011
Posts: 897
Likes: 2
From: NJ
Year: 2004 WJ, 1998 XJ
Model: Grand Cherokee(WJ)
Engine: 4.7 HO



