Welcome to Camaro Z28!

Welcome to CamaroZ28.Com, the ultimate Source for Camaro enthusiasts! Here you can join over 90,000 Camaro enthusiasts from around the world discussing all things related to Camaros and more. You are currently viewing as a guest which gives you limited access to view discussions

To gain full access to our forums you must register for a free account. As a registered member you will be able to:
  • Participate in over 40 different forums and search/browse from over 5 million posts.
  • Upload your Camaro details to your Garage
  • Post photos, respond to polls and access other special features
  • Gain access to our free marketplace to buy, sell and trade Camaros, parts and more.
All this and much more is available to you absolutely free when you register for an account, so join our community today today!

If you have any problems with the registration process or your account login, please contact support.


Go Back   CamaroZ28.Com Message Board > 1967-2002 F-Body Technical Discussion > General 1967-2002 F-Body Tech
Sign in using an external account
Register Forgot Password?
Register Garage Photos Blogs FAQ Members List Social Groups Links Calendar Search Today's Posts Mark Forums Read Z28LiveVendor Directory


Reply Post New Thread
 
 
LinkBack Thread Tools Search this Thread Display Modes
Old 06-22-2013, 10:57 PM   #1
Registered User
 
Join Date: Aug 2012
Posts: 3
Thunk from rear and swerve on hard acceleration

Hi, my first post here.
Like the title says, I have a loud thunk from my rear and the car swerves on hard acceleration. It's a '94 Z28. I feels like this; when it is punched hard, the rear end dips on the right side, there is a thunk or bang, and I must counter-steer to prevent me from going off the road. I checked all underneath and could find nothing obvious. I pried all the bushed joints, even pulled a couple off to make sure. I thought sure there must have been a bad bushing from the feel of the problem. Springs look and feel good. There are no witness marks anywhere. I checked all bolts and welds I could see or pry with a bar.
Does anybody have a clue as to what I'm missing? I thought from the way it feels that I would find something obvious. But no.
Thanks,
JiM
This ad is not displayed to registered members.
Register your free account today and become a member on CamaroZ28.com!
BikerJim is offline   Reply With Quote
Old 06-22-2013, 11:14 PM   #2
Registered User
 
Join Date: Jul 2002
Location: Friendswood, TX, USA
Posts: 3,738
Re: Thunk from rear and swerve on hard acceleration

Check your trans. mount and the torque arm mount at the trans. There are a couple of companies that make "Poly" replacement mounts for these.
__________________
NQR Racing
Blk 84 Z28 (race car)
Wht 97, M6, SS, Conv., Bld. #35, Free Mods., 160* thermo., 3:73 Gears, MSD Coil & Wires
14.045 1/4m @ 99.52mph, 3816lb., sea level, 87*
Z28SORR is offline   Reply With Quote
Old 06-23-2013, 01:21 AM   #3
Registered User
 
Join Date: Aug 2012
Posts: 3
Re: Thunk from rear and swerve on hard acceleration

Thanks Z28SORR,
The track bar mounting looks fine and is stiff. I was going to check on the trans mount tomorrow. But I don't see how that could make the whole car shift around the way it does. Stranger things have happened before I suppose. It just "feels" like its related to rear end linkage somehow. But I'll check never the less. Thanks.
JiM
BikerJim is offline   Reply With Quote
Old 06-23-2013, 08:58 AM   #4
Super Moderator
 
Injuneer's Avatar
 
Join Date: Nov 1998
Location: Hell was full so they sent me to NJ
Posts: 40,795
Garage
Re: Thunk from rear and swerve on hard acceleration

I assume your bushing check included the bushings for the track bar (aka panhard bar)? Is it possible the right rear shock is bad, allowing the rear to dip excessively on sudden acceleration? As the right rear drops and the panhard rod rotates downward, it pushes the body of the car slightly to the right.

The sudden drop may also indicate a broken end link or worn bushings on the front or rear sway bar.
__________________
Fred

94 Formula A3+1: 381ci all-forged stroker - Callies Stealth, Oliver 5.85 billet rods, BME nitrous pistons / CNC LT4 heads / Comp Cams custom solid roller / TH400 + GearVendors OD / Strange 12-bolt - 4.11's / 300-shot N2O / Spohn suspension / 6-pt roll bar with integrated SFC's / AutoMeter instrumentation / MoTeC M48Pro engine management system / a few other odds 'n ends. 800HP/800LB-FT at the flywheel.
Injuneer is offline   Reply With Quote
Old 06-23-2013, 07:24 PM   #5
Registered User
 
Join Date: Aug 2012
Posts: 3
Re: Thunk from rear and swerve on hard acceleration

Thanks Injuneer,
Yes, the traction bar and bushings look OK. I'm trying to remember which way I have to counter-steer. I seem to remember the rear dipping and shiftong to the left however, not the right. But my memory is failing me right now, and it is a real pain to get it off the stands to see. I will add however that it is a fairly violent thing. Not subtle at all.
Also, under normal driving, it handles just fine, with the exception of a constant pull to the right, which I put down to a front end alignment issue, and does not feel at all related to this. 'Course I could be wrong.
JiM

Last edited by BikerJim; 06-23-2013 at 07:31 PM.
BikerJim is offline   Reply With Quote
Old 06-25-2013, 11:22 AM   #6
Registered User
 
Zfbod94's Avatar
 
Join Date: Aug 2012
Location: South Jersey
Posts: 134
Re: Thunk from rear and swerve on hard acceleration

Do you have a stock panhard bar? Before I replaced mine, one day i got on it hard and the stock one flexed real bad and actually spun me out. Luckily I was on a back road with no one on it.

Just something else to check for.
__________________
1994 Z28....SOLD
1994 Honda Civic LX 1.5L....not gona be riced
Zfbod94 is offline   Reply With Quote
Old 06-25-2013, 09:40 PM   #7
Registered User
Premium Member
 
GaryDoug's Avatar
 
Join Date: Jul 2010
Location: Florida West Coast
Posts: 323
Garage
Re: Thunk from rear and swerve on hard acceleration

Is it possible he has a slipping/broken clutch cone in the rear axle? There is a procedure in the service manual describing a test of the limited slip axle operation using part of an axle remover tool and a torque wrench.
__________________
1998 Trans Am, LS1, Automatic, stock all the way.
GaryDoug is offline   Reply With Quote
Old 06-25-2013, 09:40 PM
 
Reply Post New Thread

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

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
Trackbacks are On
Pingbacks are On
Refbacks are On



All times are GMT -5. The time now is 05:34 PM.


Powered by vBulletin® Version 3.8.6
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
SEO by vBSEO ©2011, Crawlability, Inc.
Garage Plus vBulletin Plugins by Drive Thru Online, Inc.
Copyright © 1996-2013 CamaroZ28.Com. All rights reserved.