drivetrain noise when i let off the gas - JeepForum.com
 
LinkBack Thread Tools
post #1 of 11 Old 03-09-2010, 11:09 AM Thread Starter
leolufse
Registered User
2006 TJ Wrangler 
 
Join Date: Apr 2003
Location: Atlanta
Posts: 242
drivetrain noise when i let off the gas

When I'm on the highway and let of the gas and coast I begin to hear what sounds like roaring tire noise. If I put the gas back on, it goes away.
Its not super loud nor does it sound/feel like anything is "loose".
The jeep is a sport with the normal d30 and d44 axle combo, 3.73 gears, and 6 speed manual. Very low miles (22,000).
Its got brand new tires and all fluids changed and none of that made a difference.
Perhaps it is normal, but my 01 didn't seem to do this.
Is there something I should check?



leolufse is offline  
Sponsored Links
Advertisement
 
post #2 of 11 Old 03-09-2010, 11:36 AM
Hotrod97z
Registered User
 
Hotrod97z's Avatar
2003 TJ Wrangler 
 
Join Date: Jan 2004
Location: .....
Posts: 185
An incorrect ring/pinion setup is possible, but not likely and shouldn't be an issue if it only has 22k miles. It could be a bearing or a U-joint. Have you checked the diff fluid to make sure its full? Is it coming from the front/back/both? Have the gears been changed? How loud is it? All terrain and Mud terrain tires have inherent noises.

Alan

'03 TJ
Hotrod97z is offline  
post #3 of 11 Old 03-09-2010, 12:43 PM
Ulumanati
Registered User
2004 TJ Wrangler 
 
Join Date: May 2007
Location: Texas
Posts: 355
I've got the exact same problem and was told it had to do with the rear pinion bearings.. Either going bad or lost their preload. And mine only has 20k miles too which is why I was surprised

2004 Silver Jeep Rubicon
6" Nth Degree Longarm Kit
Ulumanati is offline  
post #4 of 11 Old 03-09-2010, 12:49 PM
VanBCguy
Web Wheeler
 
VanBCguy's Avatar
1999 WJ 
 
Join Date: Jun 2009
Location: Vancouver
Posts: 2,036
VanBCguy is offline  
post #5 of 11 Old 03-09-2010, 02:05 PM
ps49556n
Registered User
2006 TJ Wrangler 
 
Join Date: Oct 2009
Location: NYC
Posts: 145
We need more detail of this noise...I know when I am driving there is always noise when you are in between putting torque to the drivetrain and no power at all...this is the trans making noise.
ps49556n is offline  
post #6 of 11 Old 03-09-2010, 04:00 PM Thread Starter
leolufse
Registered User
2006 TJ Wrangler 
 
Join Date: Apr 2003
Location: Atlanta
Posts: 242
Its subtle, but if anything I hear it more on the right (passenger) side and rear.

The jeep has stock suspension and gears. The noise is there when I let of the gas in gear. Pushing in the clutch doesn't affect the noise. If I power back on the gas, it stops. If I let of the gas its there again.

When I say roaring tire noise, think of mud terrain lugs rolling on asphalt. Its not my tires because the sound stops when I stop coasting. It is a very on/off.

I had a bad wheel bearing on a car once and it was very different than this.
It would get louder with speed and coasting or power didn't make it stop.

I would guess ring and pinion noise from the rear, but the fluid is fresh and full. I changed it with RP, but it was doing the exact same thing on the stock fluid. The RP didn't make it worse or better.

Tell me about "rear pinion bearing pre-load". Is this somethig I can check/adjust?
leolufse is offline  
post #7 of 11 Old 03-09-2010, 04:12 PM
Ulumanati
Registered User
2004 TJ Wrangler 
 
Join Date: May 2007
Location: Texas
Posts: 355
Yes what your describing is exactly what I have. Its like a rumble as soon as you let off the gas, they thought it was my tires but I verified that it isnt that or my driveshaft for that matter. The only thing is that mine happens anywhere from 30-40mph, if i let off the gas at a lower speed it doesnt happen for some reason. WHat speeds does yours happen at?

The preload has to be checked by a gear specialist who knows what they're doing, they gotta inspect the bearings to make sure they aren't going bad, and to do that they gotta open up the rear diff.

2004 Silver Jeep Rubicon
6" Nth Degree Longarm Kit
Ulumanati is offline  
post #8 of 11 Old 03-09-2010, 05:30 PM
NorCalCon
Registered User
2006 LJ Wrangler 
 
Join Date: Oct 2008
Location: Sacramento
Posts: 673
Does the Jeep have a cold air intake, or anything other than the stock setup?
NorCalCon is offline  
post #9 of 11 Old 03-10-2010, 09:56 AM Thread Starter
leolufse
Registered User
2006 TJ Wrangler 
 
Join Date: Apr 2003
Location: Atlanta
Posts: 242
Quote:
Originally Posted by NorCalCon View Post
Does the Jeep have a cold air intake, or anything other than the stock setup?
I have a banks cat back exhaust that pops and grumbles when I let off the gas, but this noise is not related to that.

Stock air intake and stock everything else.
I guess I'll just have to live with this mild noise until it gets to the point I can pinpoint exactly where it is and then figure out what it is.

leolufse is offline  
post #10 of 11 Old 03-10-2010, 10:37 AM
NorCalCon
Registered User
2006 LJ Wrangler 
 
Join Date: Oct 2008
Location: Sacramento
Posts: 673
My cold air intake makes a sucking air roaring noise when I let off the gas at speed. I just replaced a unit bearing that gave a roaring/grinding sound only when I was coasting. I first heard it when I was getting off the freeway.
NorCalCon is offline  
post #11 of 11 Old 03-10-2010, 11:22 AM
Hotrod97z
Registered User
 
Hotrod97z's Avatar
2003 TJ Wrangler 
 
Join Date: Jan 2004
Location: .....
Posts: 185
Just drive it and see if it gets worse.

Alan

'03 TJ
Hotrod97z is offline  
Reply

Quick Reply
Message:
Options

Register Now



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

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

Password:


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



Email Address:
OR

Log-in









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
Drivetrain noise?? jimmykick TJ Wrangler Technical Forum 0 12-01-2008 02:45 PM
Noise In My '89 Yj Drivetrain S.C.JEEPER YJ Wrangler Technical Forum 3 08-07-2008 07:24 PM
Noise from drivetrain GreggieAtTheBat YJ Wrangler Technical Forum 15 11-04-2007 09:59 AM
1997 TJ Drivetrain Noise fhp6 TJ Wrangler Technical Forum 0 12-10-2006 05:34 PM
Transmission/Drivetrain noise Jeeo_Geek666 TJ Wrangler Technical Forum 3 06-14-2006 07:36 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