ZR-1 Net Registry Forums  

Go Back   ZR-1 Net Registry Forums > C4 ZR-1 > C4 ZR-1 Technical Postings

Reply
 
Thread Tools Display Modes
Old 11-23-2017   #1
JThomas
 
JThomas's Avatar
 
Join Date: May 2008
Location: Okemos, MI.
Posts: 1,191
Default Vehicle Ride Height

My 1991 ZR-1 is currently 1/2 lower in the left rear corner than the right rear of the car. The car has 119,000 miles, but all suspension bushings, etc. seem to be in good shape.

Is there an adjustment in the suspension system that I could make, to raise the left rear corner of the car? Or should I consider replacing the spring? Is there any explanation as to why the car would be lower in the left rear corner as oppose to the other? (My thoughts would be either excessive weight on the left side of the car, or maybe because there is always a driver and not necessarily a passenger, leading to wear, or launches where load is displaced to the left rear?)

I'm the second owner of the car and it has been a project for a year now, but seeing the car "tilted" is really starting to bother me.

Suggestions?
__________________
Joe Thomas
Corvette Club of Michigan
NCRS-Michigan Chapter Member
NCM Master Ambassador
NCM Lifetime Member
Former NCM Board Member
1991 ZR-1 Melon Copper Metallic/Black
1992 ZR-1 Bright Red/Black (Sold)
1995 ZR-1 Bright Aqua/Gray (Sold)
2012 ZR1 Super Sonic Blue / Dark Titanium
JThomas is offline   Reply With Quote
Old 11-23-2017   #2
BigIke
 
Join Date: Aug 2014
Location: Montgomery TX
Posts: 263
Default Re: Vehicle Ride Height

C4's do that. I put a loner bolt in the right rear, made it better.

Sent from my SM-G950U using ZR-1 Net Registry mobile app
__________________
1991 White ZRJuan #1616
Mileage: 56K Sept-14 -- 113k May-18!!!
God Damn I Love This Car!
BigIke is offline   Reply With Quote
Old 11-24-2017   #3
RussMcB
 
Join Date: Jan 2015
Location: Marietta, GA USA
Posts: 1,160
Default Re: Vehicle Ride Height

Quote:
Originally Posted by BigIke View Post
C4's do that. I put a longer bolt in the right rear, made it better.
Same here. I did a bit of measuring, couldn't find an obvious reason for it. I bought the rear lowering kit (longer bolts). I considered shims between the spring and the chassis but didn't want to screw it up. Plus, I'v since seen plenty C4 owners say to not worry about it. It's a challenge making ride height adjustments on one rear side because the single transverse
spring is bolted to the chassis in the middle of the car.

You can always convert to coil-overs. :-)
RussMcB is offline   Reply With Quote
Old 11-24-2017   #4
WVZR-1
 
Join Date: Oct 2004
Posts: 1,890
Default Re: Vehicle Ride Height

It sounds as if you're trying to measure from ground to quarter panel lip though the wheel center-line. Not done that way.

Use the trim height dimensions in the 3 section of the FSM. If you've significant issues with those dimensions you go further for diagnostics.
WVZR-1 is offline   Reply With Quote
Old 11-24-2017   #5
JThomas
 
JThomas's Avatar
 
Join Date: May 2008
Location: Okemos, MI.
Posts: 1,191
Default Re: Vehicle Ride Height

Thanks for the information.
__________________
Joe Thomas
Corvette Club of Michigan
NCRS-Michigan Chapter Member
NCM Master Ambassador
NCM Lifetime Member
Former NCM Board Member
1991 ZR-1 Melon Copper Metallic/Black
1992 ZR-1 Bright Red/Black (Sold)
1995 ZR-1 Bright Aqua/Gray (Sold)
2012 ZR1 Super Sonic Blue / Dark Titanium
JThomas is offline   Reply With Quote
Old 11-25-2017   #6
Hib Halverson
 
Join Date: Jun 2005
Location: CenCoast California
Posts: 899
Default Re: Vehicle Ride Height

An unfortunate problem during the C4 years was sometimes uneven distances between body parts and tires.

It was said earlier that the only proper way to measure trim height is per the FSM which does not index body part position in space to trim height. I'd do that, first, to see if you really have a problem with trim height or if the problem is how the body sits on the chassis structure.

If there is a problem with suspension, that needs to be addressed with repair of either spring, control arm, control arm shafts, bushings or frame sections near suspension mountings.

If the problem is with body you may or may not be able to fix that.

Lastly, using one longer/shorter rear spring bolt may make the car look right but, if there was no preexisting problem with the chassis, you have created one by having different length rear spring bolts.
__________________
Hib Halverson
Technical Writer
former owner 95 VIN 0140
current owner 19 VIN 1878
Hib Halverson is offline   Reply With Quote
Old 11-25-2017   #7
JThomas
 
JThomas's Avatar
 
Join Date: May 2008
Location: Okemos, MI.
Posts: 1,191
Default Re: Vehicle Ride Height

Got it, thanks Hib.
__________________
Joe Thomas
Corvette Club of Michigan
NCRS-Michigan Chapter Member
NCM Master Ambassador
NCM Lifetime Member
Former NCM Board Member
1991 ZR-1 Melon Copper Metallic/Black
1992 ZR-1 Bright Red/Black (Sold)
1995 ZR-1 Bright Aqua/Gray (Sold)
2012 ZR1 Super Sonic Blue / Dark Titanium
JThomas is offline   Reply With Quote
Old 11-28-2017   #8
Starman
 
Starman's Avatar
 
Join Date: Sep 2008
Location: Speedway, IN
Posts: 133
Default Re: Vehicle Ride Height

I fought with this for years and finally figured out that I screwed the car up when I rebushed the rear suspension and torqued the bolts in droop. That causes the strut rods to bind. You might try loosening the bolts at both ends (1 is camber adjuster) and retorque to proper values. You will need a way to jack the car when you do this. Then the car should be very adjustable with the spring bolts. It should not take much of an adjustment for cosmetic perfection. As previously stated correct ride height is measured from the frame.


Sent from my iPhone using ZR-1 Net Registry
Starman is offline   Reply With Quote
Old 11-28-2017   #9
S.hafsmo
 
S.hafsmo's Avatar
 
Join Date: Nov 2016
Location: Norway
Posts: 397
Default Re: Vehicle Ride Height

Height adjustable suspensions should, if possible, be adjusted with the vehicle standing on 4 individual scales to ensure correct weight distribution. Ride height is not just cosmetic.



Corner balancing

Edit: I am aware you're not running coils, just intended to mention other effects of uneven ride height.
__________________
- '90 ZR-1
S.hafsmo is offline   Reply With Quote
Reply

Thread Tools
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

Forum Jump


All times are GMT -4. The time now is 06:42 AM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Copyright ZR-1 Net Registry 2020