Rear end whine -
LinkBack Thread Tools
post #1 of 8 Old 04-24-2005, 06:57 PM Thread Starter
Registered User
Join Date: Nov 2003
Location: WPB, Florida
Posts: 34
Rear end whine

Ok guys,

I'm not too active on this board, so I really appreciate anyone that helps someone like me that doesn't contribute much. My mom has a 99 JGC, 2WD, 4.0L. It has 80,000 miles on it.

Lately, my mother has been saying that a whirring noise is coming from the back of the Jeep. I realize that "my car is making a noise" is the hardest thing to diagnose over the internet, so I'll do my best to describe it.

Its definitely a noise that increases in pitch with velocity. You can only hear it when there is a torque on the driveshaft (i.e., when coasting, it goes away). Its loudest while accelerating (I've only heard it once, and I wasn't driving, otherwise I would have put various loads on it to see how it changed). If you throw the tranny in neutral, it goes away completely, so its not engine related.

The noise doesn't decrease in pitch once you shift, so I think its only dependant upon the angular velocity of the driveshaft, and not the transmission.

I change the diff fluid at 60,000 miles with 75W90 Synthetic Gear Oil. At the time, the old oil looked old, but nothing out of place. I checked the rear diff to see if perhaps the oil had leaked out, but the area was bone dry. I did not have time to climb under the car and actually check the diff oil level.

At 78,000 miles, I flushed and filled the trans and put a new trans filter on. After that I drove the car for about 3 days with no incident before I went back to school.

My guesses are either that there is something wrong with the differential, wheel bearings, halfshafts, or mabye the U-joints (I don't even know if the car has U-joints).

Oh, and the diff is just a regular open diff, no LSD.

Anyone that has any idea of what this noise might be, your experience is greatly appreciated. If I can give you any more information, just ask! Thanks alot guys!

ddombrowski is offline  
Sponsored Links
post #2 of 8 Old 04-24-2005, 08:37 PM
Registered User
Join Date: Oct 2004
Location: Quad Cities, IL
Posts: 229
It sounds like the rear end might be failing. Mine was doing the same thing and I had to have it rebuilt.

'97 Grand Cherokee Laredo 4.0 I6
K&N FIPK Gen. 2
JBA Cat-Back Exhaust
Hypertech 93 Octane Tuning
Rancho 2" Coil Spring Lift System
ProComp ES3000 Shocks
ProComp ES2000 Steering Stabilizer
Daystar Front/Rear Sway Bar Bushings
Optima Yellow Top Battery
American Racing Chrome Pythons (15x8)
BFG All Terrain T/As 235/75/15
Sylvania SilverStar Headlamps/Foglamps --- TRADED!

'03 Ford SVT Focus <----The new ride
tehpwnt is offline  
post #3 of 8 Old 04-24-2005, 10:02 PM
Registered User
Join Date: Jun 2003
Location: Illinois (PRI)
Posts: 356
CK the diff, take the cover off, and have a look see? Pinion bearing can make that sound too......Let us know what you find out.

96 GC 117K 4.0
Retired guard 20yrs
MOS 63H 11B 43E
PDshooter is offline  
post #4 of 8 Old 04-25-2005, 08:23 AM
Registered User
Join Date: Jan 2005
Location: San Diego
Posts: 1,439
also check the carrier bearings for play. theyre notorious for going out.

1998 ZJ - 36's & bent unibody - RIP
2004 WJ - Expedition build
2011 A4 - DD
PumaZJ is offline  
post #5 of 8 Old 04-25-2005, 08:27 AM
Registered User
Join Date: Jun 2004
Location: UK
Posts: 26
Hi all

If the carrier bearings are out, is this a shim/preload adjustment, or does that mean they're shot and need replacement?
Tim750r is offline  
post #6 of 8 Old 04-25-2005, 08:37 AM
Texas ZJ1
Jeep Jedi Master
Texas ZJ1's Avatar
1994 ZJ 
Join Date: Mar 2003
Location: Omaha
Posts: 20,402
I'd replace them.


04 4.7 HO, limited
04 4.7 HO, Overland

08 Z71 Suburban, front leveling kit with rear spacers. 285/65 18s Nitto TerraGrappler G2s

94 5.9 Laredo 6.5 RE lift with 35 Maxxis Bighorns
and 33 Bridgestone Duelers
Detroit and true trac
Red Jeep Club Member
Texas Jeep Owner #6
USN Jeep Club #4

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


For your performance needs:

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

Texas ZJ1 is offline  
post #7 of 8 Old 04-25-2005, 09:26 AM
Registered User
Join Date: Jun 2004
Location: UK
Posts: 26
If you replace the carrier bearings, do you have to do the whole ring-pinion preload alignment thing?

Are there any particular symptoms of the carrier bearings going? Mine's making a sort of chuff-chuff but can't decide if its wheel bearings, carrier bearings or LSD clutches...

Its done 103K, so probably all 3!
Tim750r is offline  
post #8 of 8 Old 04-27-2005, 09:39 AM Thread Starter
Registered User
Join Date: Nov 2003
Location: WPB, Florida
Posts: 34
Thanks everyone

Thanks for everyone's suggestions. I'll be taking a look at those bearings the next time I'm under the car. I think if anything I'll be going with a rebuild kit and just have it installed since I won't be around (I go to school pretty far away from where my parents live) to do it.

I think its pretty sad that differential bearings would go after 80,000 miles. My volvo has 190,000 on it, and my BMW has 145,000. I guess anything can fail at any time, but this is the first I've seen of something like this.

Thanks again for the help guys.
ddombrowski is offline  

Quick Reply

Register Now

In order to be able to post messages on the forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Please enter a password for your user account. Note that passwords are case-sensitive.


Confirm Password:
Email Address
Please enter a valid e-mail address for yourself.

Email Address:


Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page

Similar Threads
Thread Thread Starter Jeep Forums Replies Last Post
97 ZJ rear end whine warrior23 ZJ Grand Cherokee Forum 1 08-20-2009 10:33 PM
Rear end whine Jeep Brian WK Grand Cherokee & XK Commander Forum 2 01-28-2007 12:47 PM
Help Please- Rear End Whine oregon2 ZJ Grand Cherokee Forum 1 09-17-2006 08:06 PM
ZJ Rear End Whine at 40+ MPH FWombat ZJ Grand Cherokee Forum 3 07-13-2005 06:45 PM
rear end whine? 93_zj ZJ Grand Cherokee Forum 6 12-15-2004 01:13 PM

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are On

For the best viewing experience please update your browser to Google Chrome