Ride height adjustment issues
Thread Starter
Instructor
Joined: Mar 2017
Posts: 221
Likes: 15
From: Ijamsville Maryland
Ride height adjustment issues
Thanks in advance. I am presently undergoing the rear suspension swap using 1979 components into my 1975. New TA's, 2.5" halfshafts from the '79, 2.5" wide spring from the '79 along with the '79 rear diff. I have read a number of posts and have been advised by Tony at Tony's Corvette Shop in MD that the ride height can be affected when a new spring is installed (typically increased ride height), even when using stock components. The threads I've read indicate a "longer bolt" can be used? Which bolt are we discussing? I can't, in my mind, figure out which bolt(s) related to the spring and rest of the suspension could be replaced with longer bolts that would result in a lowered ride height? It seems the inverse would be true. Take note that the swap has not yet begun and the result may be fine, but I am just worrying for the future (lol) in case I need to address the issue in some fashion. Thanks all.
Team Owner
Joined: Sep 2006
Posts: 31,221
Likes: 4,312
From: Westminster Maryland
Hi H,
With no weight on the rear spring it has considerable 'arch'.
The rear spring is designed to be almost flat from side to side when the weight of the car is on it. As the spring flattens, the car lowers to the proper 'ride height'.
When a 'stiffer' spring is used some of the 'arch' in the spring remains because there's not enough weight on the spring to flatten it. (Adding a pile of bricks to the spare tire carrier lowers the car nicely.)
The use of longer spring bolts allows some of the arch to remain in the spring, but the car ride height becomes lower.
The further the spring being used is from the standard spring's specifications, the longer the bolts will need to be.
Some people end up with 10" bolts that almost touch the ground.
Regards,
Alan
Here's an example of an almost flat spring, the standard length bolts at each end, and a car with typical ride height.
With no weight on the rear spring it has considerable 'arch'.
The rear spring is designed to be almost flat from side to side when the weight of the car is on it. As the spring flattens, the car lowers to the proper 'ride height'.
When a 'stiffer' spring is used some of the 'arch' in the spring remains because there's not enough weight on the spring to flatten it. (Adding a pile of bricks to the spare tire carrier lowers the car nicely.)
The use of longer spring bolts allows some of the arch to remain in the spring, but the car ride height becomes lower.
The further the spring being used is from the standard spring's specifications, the longer the bolts will need to be.
Some people end up with 10" bolts that almost touch the ground.
Regards,
Alan
Here's an example of an almost flat spring, the standard length bolts at each end, and a car with typical ride height.
Thread Starter
Instructor
Joined: Mar 2017
Posts: 221
Likes: 15
From: Ijamsville Maryland
Hi H,
With no weight on the rear spring it has considerable 'arch'.
The rear spring is designed to be almost flat from side to side when the weight of the car is on it. As the spring flattens, the car lowers to the proper 'ride height'.
When a 'stiffer' spring is used some of the 'arch' in the spring remains because there's not enough weight on the spring to flatten it. (Adding a pile of bricks to the spare tire carrier lowers the car nicely.)
The use of longer spring bolts allows some of the arch to remain in the spring, but the car ride height becomes lower.
The further the spring being used is from the standard spring's specifications, the longer the bolts will need to be.
Some people end up with 10" bolts that almost touch the ground.
Regards,
Alan
Here's an example of an almost flat spring, the standard length bolts at each end, and a car with typical ride height.
With no weight on the rear spring it has considerable 'arch'.
The rear spring is designed to be almost flat from side to side when the weight of the car is on it. As the spring flattens, the car lowers to the proper 'ride height'.
When a 'stiffer' spring is used some of the 'arch' in the spring remains because there's not enough weight on the spring to flatten it. (Adding a pile of bricks to the spare tire carrier lowers the car nicely.)
The use of longer spring bolts allows some of the arch to remain in the spring, but the car ride height becomes lower.
The further the spring being used is from the standard spring's specifications, the longer the bolts will need to be.
Some people end up with 10" bolts that almost touch the ground.
Regards,
Alan
Here's an example of an almost flat spring, the standard length bolts at each end, and a car with typical ride height.
