Go Back   AnandTech Forums > Social > The Garage

Forums
· Hardware and Technology
· CPUs and Overclocking
· Motherboards
· Video Cards and Graphics
· Memory and Storage
· Power Supplies
· Cases & Cooling
· SFF, Notebooks, Pre-Built/Barebones PCs
· Networking
· Peripherals
· General Hardware
· Highly Technical
· Computer Help
· Home Theater PCs
· Consumer Electronics
· Digital and Video Cameras
· Mobile Devices & Gadgets
· Audio/Video & Home Theater
· Software
· Software for Windows
· All Things Apple
· *nix Software
· Operating Systems
· Programming
· PC Gaming
· Console Gaming
· Distributed Computing
· Security
· Social
· Off Topic
· Politics and News
· Discussion Club
· Love and Relationships
· The Garage
· Health and Fitness
· Merchandise and Shopping
· For Sale/Trade
· Hot Deals with Free Stuff/Contests
· Black Friday 2014
· Forum Issues
· Technical Forum Issues
· Personal Forum Issues
· Suggestion Box
· Moderator Resources
· Moderator Discussions
   

Reply
 
Thread Tools
Old 10-12-2007, 07:38 PM   #1
jkersenbr
Golden Member
 
Join Date: Jun 2000
Posts: 1,691
Default Whining noise from rear axle

I've got a 2000 Dodge Dakota that is making a high-pitched whine from the rear axle. It's the "heavy duty" option 9" rear end WITHOUT limited slip. Has 96K miles on it and the fluid looks pretty clean. (I've only had the truck for the last 12K)

It starts as a slow whirring sound around 20MPH and increases to a whine at highway speed. The noise changes little with acceleration and deceleration.

It's made the noise to some extent as long as I had it. I just thought it was gear noise. But lately it's been getting worse.

I thought maybe I was mistaking tire noise, so put it up on jacks and ran the rear wheels off the ground...still does it.

What do you think? Are the ring and pinion toast? Or maybe just bearings?

jkersenbr is offline   Reply With Quote
Old 10-12-2007, 08:30 PM   #2
SparkyJJO
Lifer
 
SparkyJJO's Avatar
 
Join Date: May 2002
Location: Ohio
Posts: 12,216
Default Whining noise from rear axle

I'd get the differential checked out. If it is getting worse that is not a good sign.
__________________
Heatware

CO2 is evil. Stop breathing

"I have never understood why it is greed to want to keep the money that you've earned, but not greed to want to take somebody else's money." - Thomas Sowell
SparkyJJO is offline   Reply With Quote
Old 10-12-2007, 08:51 PM   #3
iamwiz82
Lifer
 
iamwiz82's Avatar
 
Join Date: Jan 2001
Posts: 30,503
Default Whining noise from rear axle

Does it only occur on acceleration?

I would guess that it's a bearing by your description. You may as well have all of them replaced if the diff is disassembled.
iamwiz82 is offline   Reply With Quote
Old 10-13-2007, 12:20 AM   #4
mrblotto
Senior Member
 
mrblotto's Avatar
 
Join Date: Jul 2007
Location: NC
Posts: 997
Default Whining noise from rear axle

U-Joints?
__________________
Quote:
Originally Posted by Via View Post
They can be healthy, but I don't want them building muscle while they're in jail. Feed them rice or something.
mrblotto is offline   Reply With Quote
Old 10-13-2007, 07:58 AM   #5
jkersenbr
Golden Member
 
Join Date: Jun 2000
Posts: 1,691
Default Whining noise from rear axle

Quote:
Originally posted by: iamwiz82
Does it only occur on acceleration?

I would guess that it's a bearing by your description. You may as well have all of them replaced if the diff is disassembled.

No it does it both accelerating and decelerating. Also coasting, even in neutral.





Quote:
Originally posted by: mrblotto
U-Joints?
The U-Joints are OK. I know what they sound like and this isn't it. They click, ping, and vibrate, they don't whine like a dying TV.


jkersenbr is offline   Reply With Quote
Old 10-13-2007, 08:13 AM   #6
Gillbot
Lifer
 
Gillbot's Avatar
 
Join Date: Jan 2001
Location: Who Cares
Posts: 28,473
Default Whining noise from rear axle

Bearing and/or gears. I've hears U-joints whine also.
__________________
My Heatware
Gillbot is offline   Reply With Quote
Old 10-13-2007, 08:51 AM   #7
iamwiz82
Lifer
 
iamwiz82's Avatar
 
Join Date: Jan 2001
Posts: 30,503
Default Whining noise from rear axle

Quote:
Originally posted by: jkersenbr
Quote:
Originally posted by: iamwiz82
Does it only occur on acceleration?

I would guess that it's a bearing by your description. You may as well have all of them replaced if the diff is disassembled.

No it does it both accelerating and decelerating. Also coasting, even in neutral.
Sounds like bearings then. Gears normally only whine on accel or decel, though it is possible to have gears whine continuously. I have never seen that personally.
iamwiz82 is offline   Reply With Quote
Old 10-13-2007, 11:52 AM   #8
woodie1
Diamond Member
 
Join Date: Mar 2000
Location: 28 27' 20"N 98 16' 20"W
Posts: 5,947
Default Whining noise from rear axle

"No it does it both accelerating and decelerating. Also coasting, even in neutral. "

That sure sounds like a bad bearing.
woodie1 is offline   Reply With Quote
Old 10-13-2007, 08:14 PM   #9
mrblotto
Senior Member
 
mrblotto's Avatar
 
Join Date: Jul 2007
Location: NC
Posts: 997
Default Whining noise from rear axle

On a slightly related note (no hijack intended), I had the rear diff changed out of my very first new vehicle: an '88 Dodge Dakota. Anyhow, for some reason I guess the real mechanics were on vacation, because a 'higher gear' rear diff was installed. My speedo would say 50, but I was actually going 60. For a few days I thought I was just going crazy 'cause I would be driving down a hill and think 'man, it feels like i'm flying down the road.....' lol

/end hijack
__________________
Quote:
Originally Posted by Via View Post
They can be healthy, but I don't want them building muscle while they're in jail. Feed them rice or something.
mrblotto is offline   Reply With Quote
Old 10-13-2007, 09:22 PM   #10
iamwiz82
Lifer
 
iamwiz82's Avatar
 
Join Date: Jan 2001
Posts: 30,503
Default Whining noise from rear axle

Quote:
Originally posted by: mrblotto
On a slightly related note (no hijack intended), I had the rear diff changed out of my very first new vehicle: an '88 Dodge Dakota. Anyhow, for some reason I guess the real mechanics were on vacation, because a 'higher gear' rear diff was installed. My speedo would say 50, but I was actually going 60. For a few days I thought I was just going crazy 'cause I would be driving down a hill and think 'man, it feels like i'm flying down the road.....' lol

/end hijack
Impossible. Dakotas read the speed well before the differential.
iamwiz82 is offline   Reply With Quote
Old 10-14-2007, 11:57 AM   #11
Gillbot
Lifer
 
Gillbot's Avatar
 
Join Date: Jan 2001
Location: Who Cares
Posts: 28,473
Default Whining noise from rear axle

Quote:
Originally posted by: iamwiz82
Quote:
Originally posted by: mrblotto
On a slightly related note (no hijack intended), I had the rear diff changed out of my very first new vehicle: an '88 Dodge Dakota. Anyhow, for some reason I guess the real mechanics were on vacation, because a 'higher gear' rear diff was installed. My speedo would say 50, but I was actually going 60. For a few days I thought I was just going crazy 'cause I would be driving down a hill and think 'man, it feels like i'm flying down the road.....' lol

/end hijack
Impossible. Dakotas read the speed well before the differential.
It doesn't matter where the speed is read as they are calibrated for a certain number of pulses per revolution. Unless you are taking speed on the rear wheel exactly, changing the gear ratio will alter the speedo unless calibrated for.
__________________
My Heatware
Gillbot is offline   Reply With Quote
Old 10-15-2007, 08:56 PM   #12
funboy6942
Lifer
 
funboy6942's Avatar
 
Join Date: Nov 2001
Location: Dyer, TN.
Posts: 13,650
Default Whining noise from rear axle

Bad bearing as suggested, or just change the diff fluid for it is low, and has been since you got the truck. The fluid can also leak into your drums so look at the tires on the insides for wetness, sign of diff leak, or brake fluid leak. But if the bearing or low, to noe, or very thin, worn oil will cause the moving sound you speak of.

Also I am not sure but does that truck us a split drive shaft? If so may want to check the bearing at the split as well.
funboy6942 is offline   Reply With Quote
Old 10-16-2007, 09:15 AM   #13
Demon-Xanth
Lifer
 
Demon-Xanth's Avatar
 
Join Date: Feb 2000
Posts: 20,551
Default Whining noise from rear axle

I don't know for sure about the '88 Dakota. But the '97 and up measure the speed off of the ring gear, so changing the gear ratio does NOT affect the speedometer calibration.

OP: for reference, your rear end is a Chrysler 9.25". You can verify this by looking at a small tag on the driver's side axle tube:
http://dodgetruckworld.tenmaga.../DemonXanth/306206.jpg
http://dodgetruckworld.tenmaga.../DemonXanth/306207.jpg (9.25" 3.55 "trac lock")

You'll need about two and a half quarts of fluid to replace your fluid, but it's a pretty easy job. You can check the fluid by simply removing the plug on the cover and sticking your finger in the hole. Also note that a possible culprit is the carrier bearing.
__________________
Heatware: Demon-Xanth
UGTZ: DemonXanth
My ride
Demon-Xanth is offline   Reply With Quote
Old 10-16-2007, 10:39 AM   #14
iamwiz82
Lifer
 
iamwiz82's Avatar
 
Join Date: Jan 2001
Posts: 30,503
Default Whining noise from rear axle

Quote:
Originally posted by: Gillbot
Quote:
Originally posted by: iamwiz82
Quote:
Originally posted by: mrblotto
On a slightly related note (no hijack intended), I had the rear diff changed out of my very first new vehicle: an '88 Dodge Dakota. Anyhow, for some reason I guess the real mechanics were on vacation, because a 'higher gear' rear diff was installed. My speedo would say 50, but I was actually going 60. For a few days I thought I was just going crazy 'cause I would be driving down a hill and think 'man, it feels like i'm flying down the road.....' lol

/end hijack
Impossible. Dakotas read the speed well before the differential.
It doesn't matter where the speed is read as they are calibrated for a certain number of pulses per revolution. Unless you are taking speed on the rear wheel exactly, changing the gear ratio will alter the speedo unless calibrated for.
I am an idiot and not sure why I posted that, because I know (and knew) you are right. My only excuse was is that I was tipsy at that point.
iamwiz82 is offline   Reply With Quote
Old 10-16-2007, 06:22 PM   #15
Subbaculcha
Member
 
Join Date: Aug 2004
Posts: 130
Default Whining noise from rear axle

Quote:
Originally posted by: iamwiz82

I am an idiot and not sure why I posted that, because I know (and knew) you are right. My only excuse was is that I was tipsy at that point.
Not necessarily...when I swapped gears on my 96 mustang gt, I had to change out the speedometer driven gear (at the transmission) to get my speedometer in sync with the new gears.
Subbaculcha is offline   Reply With Quote
Old 10-17-2007, 07:11 AM   #16
bctbct
Diamond Member
 
Join Date: Dec 2005
Posts: 4,868
Default Whining noise from rear axle

I just had the same symptom on my 05 1500 and it was the pinion bearing. Mine was covered under drivetrain warranty.
bctbct is offline   Reply With Quote
Old 10-17-2007, 11:19 AM   #17
cardiac
Golden Member
 
cardiac's Avatar
 
Join Date: Oct 1999
Location: Ask Your Mom..
Posts: 1,939
Default Whining noise from rear axle

I think bctbct hit it on the head. Find a good transmission/differential shop and have them check it. They can replace the pinion bearings and new axle seals for about $300 or so.....

Bob
__________________
My Heatware
cardiac is offline   Reply With Quote
Old 10-17-2007, 09:25 PM   #18
bctbct
Diamond Member
 
Join Date: Dec 2005
Posts: 4,868
Default Whining noise from rear axle

Check warranty because mopar has many different age/mile restrictions.
bctbct is offline   Reply With Quote
Reply

Thread Tools

Posting Rules
You may not post new threads
You may not 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

Forum Jump


All times are GMT -5. The time now is 08:50 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.