I have always noticed that my Corvette ('72 LS5) rides low in the rear. If I hit a medium dip in the road my exhausts (pipes just below rear diff.) bottom out (it probably doesn't help that my fat azz is in there!! ). So today I decided to lift it up and look around to see what all I need to do back there. From what I know about the car, I am pretty sure all the rear suspension components are original (approx. 85K miles).

Before lifting the car, I looked underneath and noticed that the leaf spring (HD 7 leaf) is sitting perfectly flat. No arch at all. Is this normal??

Right now I have it up in the air with the rear spare carrier out of the way. Other than dirty, everything looks OK. The bushings aren't too bad. Nothing looks bent. Other than some minor surface rust/scale, the trailing arms look OK. I just figured that I would post this message and see if anyones has recommendations for what I should check while under there.

My primary concern is the leaf spring. Any help would be appreciated!!

Mark it sounds like maybe your rear shocks are worn out . I think your leaf springs seem normal for car on the ground. See if there is alot of extra bounce in your car by pushing down on the rear fender, car should go down and up and stop with no extra play. Good luck that's all I got.

Mike.

I had the same problem on my 70. When I would hit a good bump it would grind the exhaust clamp. It also sat low in the back. I replaced the leaf spring and all the bushings. Now the car sits up about 2 in inches higher and it don't hit.

A flat spring is most likely the culprit. If you don't have at least some positive arch in your spring, then it is time for a replacement. Unfortunately, nobody is producing a "correct" spring from both a cosmetic and functional standpoint. The repro springs that are out there either look different than the original or they give a different ride height. If your shocks are worn, they may allow a little extra bounce but they provide very little adjustment to the ride height.

The BEST procedure for removing the rear spring is in your 72 GM Service Manual. Please be careful, follow the directions, and also ensure that you have high quality jack stands under the car.
Gary

Thanks for the responses!!!

Mike: The shocks are fairly new and appear to still be in good shape.

Larry: I had a good friend come by last night. He is a auto mechanic. He agreed that the spring and spring link/bushings should be replaced. I am shopping around right now!

Gary: I have known for a while that I had issues with the rear suspension. So I have been occassionally checking in to the various parts suppliers for the best spring vs. cost. I do want to go back with an original type spring. I believe that Doc Rebuild has the best products for my project. I am still going to look a little more, but I think the Good Doctor is the way to go! Thanks also for the heads-up on the GM Service Manual! And I do have the car up on good stands and my two jacks are also in place as back-up. No matter how many times I've crawled underneath a car, it still scares the heck out of me!!! Better safe than sorry!!

Thanks again everyone!!!!!

Mark

Mark,

I replaced the rear spring on my '70 late last summer. I too had noticed a bit of scraping when hitting some bumps and several people at various car shows I attended last year noted that the spring looked a bit flat. I had looked into the mono springs as several folks had told me that I wouldn't believe the difference they made in the handling and ride of their cars after the swap, but I wanted to stay more original with mine so opted for a steel replacement.

I checked prices at a lot of sites and catalogs (they were all pretty close, but the tiebreaker was the cost of the misc supporting parts), ended up getting the spring, poly bushings, and misc hardware from Corvette Central. I had the car up in the air for a new exhaust system and shocks as well so having all the pipes out of the way made for more elbow room. The trickiest part of the whole operation (for me anyway) was getting the center mounting plate back in place. The new spring had more arch to it than the old one so that made it a bit dicey getting the bolts started. I didn't want to put any tension on the spring prior to having them at least started a turn or three for fear that the darn thing would come flying out of there. I'd suggest looking for slightly longer bolts to make that part of the reassembly easier. An extra floor jack also made the take-apart and put-back-together much more of a breeze.

Other than that it was a relatively simple task. It probably took me longer to do than most other driveway wrenchers, but managed to the whole project (exhaust, rear spring, and shocks at all four corners) by myself over most of a weekend. It took a couple of test rides to get the tension on the spring dialed into were it felt good, but after that no more scraping sounds when encountering bumps in the road!

Good luck...!!!

Mark -- replace the spring bushings; these flatten with age. You might also check to ensure your spring bolts are the stock length.

Well, it looks like my spring is OK. The spring links and bushings are shot. I also removed my shocks and they are shot as well!! Ordered the shocks yesterday from The Last Detail. Hope to have everything back together by mid next week.

Thanks for all the responses!! I will post an update when I get it back together.

Mark