Differential Clunk/Growl resolved! - Pontiac GTO Forum
User Tag List

Reply
 
LinkBack Thread Tools Display Modes
post #1 of 12 (permalink) Old 02-10-2013, 01:24 PM Thread Starter
 
YellO5LS2's Avatar
 
Join Date: Jan 2011
Location: Florida
Posts: 112
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Differential Clunk/Growl resolved!

Ok, I haven't been on here in a year because some senior members didn't like my opinions on Amsoil, but I'm back to just say that I've learned some new stuff about GTO diffs that may come in handy to those who are considering fluid services. My diff started grinding and clunking a few weeks ago and, even though I'd changed the fluids and had no problems until now, I researched again on gear oils. Anyway, I took my car to the dealer and had them swap out my Amsoil 75w140 with AcDelco 75w90 LS Series gear oil. Friction modifier is already premixed, however they still have a friction modifier sold separately for the trucks and SUV models. It's a type "F" apparently and is fine in the GM performance models as well. It fixed my problem completely. It also cured the noises that I figured could be bad bearings, bushings, half shafts, etc. Really nice considering I'd already budgeted for my entire tax refund being burnt in 2 days

Reason for the fluid change (courtesy of the Corvette Tech, not my "opinion") was that older model differentials (01-07) had metal/metal clutches which were prone to wear and make noise quicker without a "right" friction additive. GTOs are filled with a 140winter viscosity from the factory, and the friction modifier becomes useless as the oil wears slightly but retains its hot flow properties. Nowadays, the clutches have been redesigned (including new GTO rears). The good news is that if your differential noise is only due to worn fluid, then the new GM recommended fluid will fix the issue and the differential will be fine.

Advice? Buy the fluid at GM Parts Direct: Your direct source for Genuine GM Parts cause its only $12 per quart there as opposed to $22 at the dealer (PN 88862624). I hope this info is helpful to anyone who's become worried or unsure about their cars!
YellO5LS2 is offline  
Sponsored Links
Advertisement
 
post #2 of 12 (permalink) Old 02-10-2013, 01:32 PM
 
HP11's Avatar
 
Join Date: Apr 2009
Location: San Bernardino, Ca.
Posts: 2,603
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 24 Post(s)
Quote:
Originally Posted by YellO5LS2 View Post
Advice? Buy the fluid at GM Parts Direct: Your direct source for Genuine GM Parts cause its only $12 per quart there as opposed to $22 at the dealer (PN 88862624).
Looking on the site you linked to, that part number yields a price of $13.06 and if you add the shipping charges ($12.95) it comes up to $26.01.

2005 Pontaic GTO - CGM 6 Speed (My car)
2017 Chevrolet Colorado 2WT (My daily driver)
2010 Mercedes Benz C300 Sedan (Wife's car)
2014 Kia Rio LX (Wife's daily driver)
HP11 is offline  
post #3 of 12 (permalink) Old 02-10-2013, 01:59 PM Thread Starter
 
YellO5LS2's Avatar
 
Join Date: Jan 2011
Location: Florida
Posts: 112
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Holy crap, I didn't think of shipping. Well I guess it's cheaper in person then. Good lookin out. Can't believe it's that pricey though.
YellO5LS2 is offline  
 
post #4 of 12 (permalink) Old 02-10-2013, 03:37 PM
Super Moderator
 
GTO JUDGE's Avatar
 
Join Date: May 2005
Location: Lancaster, PA
Posts: 8,433
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 19 Post(s)
Garage
Just for reference: This sticky was created: 08/28/2007
https://www.gtoforum.com/f3/growling-...ng-rear-14102/


President: GTO Association of America
www.gtoaa.org


GTO JUDGE is offline  
post #5 of 12 (permalink) Old 02-10-2013, 03:49 PM Thread Starter
 
YellO5LS2's Avatar
 
Join Date: Jan 2011
Location: Florida
Posts: 112
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by GTO JUDGE View Post
Just for reference: This sticky was created: 08/28/2007
https://www.gtoforum.com/f3/growling-...ng-rear-14102/

Yeah I noticed that after I posted. Been off the forum for a while but remember a lot of people making new threads about the same noises. Just excited I don't need a new diff
YellO5LS2 is offline  
post #6 of 12 (permalink) Old 02-10-2013, 04:13 PM
Super Moderator
 
GTO JUDGE's Avatar
 
Join Date: May 2005
Location: Lancaster, PA
Posts: 8,433
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 19 Post(s)
Garage
Quote:
Originally Posted by YellO5LS2 View Post
Yeah I noticed that after I posted. Been off the forum for a while but remember a lot of people making new threads about the same noises. Just excited I don't need a new diff
Under warranty, the changing out of the fluids was the first step in seeing if the noises stopped, to many me included it didn't. Then the rear was changed at the recommendation of the service manager.

After my new rear was replaced, shortly after I was getting the growling. They changed it all out added new FM and after a day of driving it, it stopped. The rear is quiet. Its good you didn't need a new rear. Lots of guys new to this car have no clue on this issue and it was a common one.

President: GTO Association of America
www.gtoaa.org


GTO JUDGE is offline  
post #7 of 12 (permalink) Old 02-10-2013, 10:03 PM Thread Starter
 
YellO5LS2's Avatar
 
Join Date: Jan 2011
Location: Florida
Posts: 112
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Yeah I was crossing my fingers as I watched the tech drain the fluid. Came out mildly cloudy but no metal or metallic color. BIG sigh of relief. I was actually surprised, as I've been using the old spec fluid since the car was born. How much did the new diff run you, if you don't mind my asking?
YellO5LS2 is offline  
post #8 of 12 (permalink) Old 02-10-2013, 10:23 PM
 
kilkm68's Avatar
 
Join Date: May 2011
Location: Peoria, IL
Posts: 217
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Garage
I had a similar problem with an '02 AWD Chevy Venture Van. It started making a howling/grinding noise when making sharp turns just after the warranty expired! They quoted me a fix of $5500. One service manager told me of a TSB put out by GM about changing the versi-track fluid with a new type they had developed. $50 per quart! He said to change the fluid, take it to a parking lot and crank the wheel as hard as I could and drive it around in a circle for 5 min. I did and within 1 min. the noise stopped. Never had any more trouble with it after that. Lots of other problems with that POS, but at least I didn't have to spend 5K on it. I got on line and read a lot of people with the Chevy Venture and Olds Bravada having this problem. They had a class action suit against GM over it in Canada. Should have been a recall.
kilkm68 is offline  
post #9 of 12 (permalink) Old 02-11-2013, 06:10 AM
Super Moderator
 
GTO JUDGE's Avatar
 
Join Date: May 2005
Location: Lancaster, PA
Posts: 8,433
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 19 Post(s)
Garage
Quote:
Originally Posted by YellO5LS2 View Post
Yeah I was crossing my fingers as I watched the tech drain the fluid. Came out mildly cloudy but no metal or metallic color. BIG sigh of relief. I was actually surprised, as I've been using the old spec fluid since the car was born. How much did the new diff run you, if you don't mind my asking?
Was replaced under warranty. They did not rebuild them. The entire unit came as one part number and is a Dana rear. Dana made good on them.

Now with the warranties past I would think rebuilding them would be cheaper than replacing.

President: GTO Association of America
www.gtoaa.org


GTO JUDGE is offline  
post #10 of 12 (permalink) Old 05-29-2013, 10:17 AM
 
Join Date: May 2013
Posts: 15
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
I have an issue similar to this. Under moderately light acceleration I can feel a popping through my arm rest. It is really not audible. It usually pops 3 to 5 times on then stops as I get to moving past 5 to 15 mph. It will do it in first or second gear. I have an A4 and it changes to second really fast under light acceleration which I am sure is normal. I am getting concerned about this! Rear CV's? Or is it related to this post? 06 A4
1bert1 is offline  
Sponsored Links
Advertisement
 
Reply

  Pontiac GTO Forum > The 2004-2006 GTO > Service, Maintenance and Technical Discussion

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Pontiac GTO Forum 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 email address for yourself.

Email Address:
OR

Log-in











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
Display Modes
Linear Mode Linear Mode



Similar Threads
Thread Thread Starter Forum Replies Last Post
Left tire humming/growl at low speed yellow bullet Service, Maintenance and Technical Discussion 5 03-07-2010 09:37 AM
Looking for Deeper Growl 06black60 Intake and Exhaust Discussions 25 11-03-2009 01:12 AM
Rear End Clunk? SAMMY The Lounge 3 05-16-2008 12:45 PM
Yet another clunk tano Drive train, suspension, alignment and brakes. 5 10-01-2006 02:33 PM
Early Midlife Crisis Resolved argus Member Introductions 6 07-03-2006 08:44 AM

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 On
Pingbacks are On
Refbacks are On

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