clunking from rear end when shifting hard - Pontiac GTO Forum
User Tag List

 
LinkBack Thread Tools Display Modes
post #1 of 8 (permalink) Old 06-07-2009, 01:25 PM Thread Starter
 
Join Date: Jun 2009
Posts: 27
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
clunking from rear end when shifting hard

Just got a 2004 GTO...I got into it today and shifted it hard and heard a clunking coming from the rear, wondered if anyone has any ideas as to what is making the noise...possible U joint? any suggestions would be much appreciated!
goatfan2004 is offline  
Sponsored Links
Advertisement
 
post #2 of 8 (permalink) Old 06-07-2009, 02:50 PM
 
chilliwhiggerE's Avatar
 
Join Date: Mar 2009
Location: Hollywood, Florida originally from Pittsburgh, Pa.
Posts: 91
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Clunk under high torque

There is a TSB (technical service bulletin) that says the crossmember / X member bushings that support the rear differential are insufficient & need to be replaced. They have a lot of play & allow excess travel. The parts are fairly inexpensive & the repair manual says it should take about 45 minutes to replace them with the proper equipment. I would double that time for the driveway. I have the same issue. I haven't done the replacement yet. I'm planing on doing it when I do the cross drilled & slotted rotors because I'll be half way there plus I'll have that weight off of the rear axle. I have to go to work but if I can locate the detailed TSB I'll post it when I get home. It has the part #, equipment & procedure. The bushings are readily available in the aftermarket. I actually plan on replacing all the bushings with more solid ones cuz the OEM ones are pathetic. Those who have done this claim that it makes all the difference in the world. I believe the entire kit is about $150 + some knuckle busting / wrench turning.

Last edited by chilliwhiggerE; 06-07-2009 at 04:38 PM.
chilliwhiggerE is offline  
post #3 of 8 (permalink) Old 06-07-2009, 06:04 PM
 
raspantienator's Avatar
 
Join Date: Nov 2007
Location: BREWSTER, NY
Posts: 1,448
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
There is also a tech bull that says some clunking is normal for the Cadillac and GTO.

Your Pontiac dealer should be able to pull up the bulletins, test drive the car with you in it, and help you decide the next course.
raspantienator is offline  
 
post #4 of 8 (permalink) Old 06-07-2009, 06:46 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
GTO JUDGE is offline  
post #5 of 8 (permalink) Old 06-07-2009, 11:15 PM Thread Starter
 
Join Date: Jun 2009
Posts: 27
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
thanks a lot for all the help! much appreciated!
goatfan2004 is offline  
post #6 of 8 (permalink) Old 06-08-2009, 04:06 AM
 
chilliwhiggerE's Avatar
 
Join Date: Mar 2009
Location: Hollywood, Florida originally from Pittsburgh, Pa.
Posts: 91
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Here's the TSB

You've gotta love the thoroughness of this:

Knocking Noise from Rear of Vehicle on Aggressive Launch or Acceleration (Install Rear Suspension Crossmember Front Mount Insulators) #04-03-09-003A - (Apr 20, 2004)
Knocking Noise from Rear of Vehicle on Aggressive Launch or Acceleration (Install Rear Suspension Crossmember Front Mount Insulators)
2004 Pontiac GTO

Built Prior to VIN Breakpoint 4L246712

This bulletin is being revised to change a torque specification within the correction procedure. Please discard Corporate Bulletin Number 04-03-09-003 (Section 03 -- Suspension).

Condition
Some customers may comment on a knocking noise coming from the rear of the vehicle. This noise occurs during an aggressive launch or acceleration and will be more common on vehicles with a manual transmission.

Cause
The cause of this condition may be contact between the body and the rear suspension crossmember.

Correction
Install insulators, P/N 90447991, and new bolts, P/N 92038482, between the body and the rear suspension crossmember using the procedure listed below.

Important
Only remove the bolts from one side of the suspension crossmember at a time, and DO NOT loosen the opposite side, until the insulator is installed on the first side and all fasteners have been tightened to the specified torque setting.

Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle in the General Information sub-section of the Service Manual. Position rear hoist.
Support the rear suspension crossmember just under the brace using an adjustable jack stand.
Remove the 3 brace to underbody bolts.
Remove the front mount bolt attaching the rear suspension crossmember to the underbody.
Lower the jack stand slightly to allow clearance between the crossmember and the underbody.

Important
When installing the insulator onto the crossmember front mount bushing, face the corrugated side upwards, so it bears against the underbody.

Install the insulator between the underbody and the upper part of the crossmember, ensuring to seat the insulator firmly onto the center of the crossmember front mount bushing.
Raise the crossmember using the jack stand until it is pressing firmly against the underbody.
With the jack stand still in position to support the crossmember, install the new front mount bolt and the 3 brace to underbody bolts. Tighten
Tighten the crossmember front mount bolt to 125Nm(92 lb ft). Use J 45059 Torque Angle Meter in order to tighten the bolt an additional 40 degrees.

Tighten
Tighten the brace bolts to 65Nm(48 lb ft).

Remove the jack stand.
Repeat steps 2 to 9 for the opposite side.
Parts Information
Part Number
Description
Qty

90447991
Insulator, Rear Suspension Crossmember Front Mount (2 Per Package)
1

92038482
Bolt, Rear Suspension Crossmember Front Mount
2

Parts are currently available from GMSPO.

Warranty Information
For vehicles repaired under warranty, use:

Labor Operation
E9407*
Rear Suspension Crossmember Front Mount Insulators -- Install
0.5 hr

There you have it. Get down & party!
chilliwhiggerE is offline  
post #7 of 8 (permalink) Old 06-09-2009, 10:25 PM Thread Starter
 
Join Date: Jun 2009
Posts: 27
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
That may be one of the most thorough things i've ever read. its sweet though! thanks a lot man, im actually installing new rotors all the way around sometime in the next week so that will be the time!
goatfan2004 is offline  
post #8 of 8 (permalink) Old 06-10-2009, 08:20 AM
 
chilliwhiggerE's Avatar
 
Join Date: Mar 2009
Location: Hollywood, Florida originally from Pittsburgh, Pa.
Posts: 91
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
If I can help it's my responsibility to do so. I also give credit where credit is due. You can thank Sarge from LS1 Performance Information - Powered by vBulletin for that nugget. He has listed every TSB for the 04' that he could. He's like a GTO god / solid dude.
chilliwhiggerE is offline  
Sponsored Links
Advertisement
 
Reply

  Pontiac GTO Forum > The 2004-2006 GTO > Drive train, suspension, alignment and brakes.

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
Rear End out of alignment Edzjk Drive train, suspension, alignment and brakes. 6 04-15-2009 05:41 PM
Overdrive, rear end questions worldrocker77 1964-1974 Tempest, Lemans & GTO Undercarriage, Frame, Transmission and Differential Discussions. 10 03-27-2009 08:34 AM
Definitive Definition Of Gto Suspension Concerns dms Drive train, suspension, alignment and brakes. 1 12-05-2008 12:47 AM
rear end question firecatsrt 1964-1974 Tempest, Lemans & GTO Undercarriage, Frame, Transmission and Differential Discussions. 9 09-16-2008 10:13 AM
Rear End rebuildable? cruiser787904 Drive train, suspension, alignment and brakes. 10 05-24-2007 09:42 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