Replacing rear spring

[MaineShark]

I have a feeling my rear spring is getting tired. It seems softer than it should be and the car doesn't quite sit level. So, with less exhaust clearance than I used to have, I think I'd like to replace it with a new (maybe slightly stiffer) spring.

How involved is the replacement procedure, for a home mechanic (ie, jack stands, not a lift)?

And, how much more complicated is it to do the replacement without removing the exhaust pipes? When he installed them, my mechanic welded them ( ad ), so removing them will be nearly impossible without damage, I think. Is it going to be possible to slip the spring out and in above the pipes?

Joe

 

[69MyWay]

Joe,

The spring will bow down and most likely hit the pipes when you pull it loose from the trailing arms.

Just jack up the car, support on the frame in front of the rear wheels. Put some liquid wrench on all the bolts and let them soak.

Remove the four bolts holding the spring to the diff, and the long bolts/studs at each end. You will want to support each end when you remove the long stud, then let it down slow, repeat on the other side. It will fall right out....less your exhaust situation.

 

[yakatak76]

maineshark,
i have been reading in the how to restore and make your corvette into a hotrod about replacing the rear spring with the new fiberglass rear spring. according to the book, it is better that the steel on easier to work with and weighs less than ten pounds as compared to the stock 44 pounds for the stock one. i will read up on it again tonight and give you some more info on it.

 

[ChuckG]

Sometimes, just replacing the rubber "donuts" will restore some of the ride height. They can be bought cheaply. Be VERY careful when you let the spring down. It will literally break your arm if it flies loose.

I wrap the spring with a rag, then put a big vice grip over the rag. I position this toward the end of the spring. I then put my floor jack under the end of the spring, using my vice grip as a "stop point". I carefully remove the bolts, then let the spring down slowly with the floor jack. Do this on both sides, then remove the 4 bolts in the center. Be careful with these bolts, as sometimes you'll find 2 longer...2 shorter bolts. If you replace them incorrectly, you can poke the end of the bolt into the diff housing and cause a leak. Don't ask me how I know this.

Also, when you re-install the spring, do not tighten or torque the 4 center bolts till the car is back on the ground with weight on the spring. If you tighten them before the weight is on the car, you run the risk of breaking one of the "ears" on the diff mount.

Hope this helps. Chuck

 

[MaineShark]

yakatak: thanks, but I already considered the fiberglass spring. For this car, and my uses of it, the weight saving doesn't justify the cost difference. It's $330 vs $120 from VBP.

Chuck: thanks for the tips. It's not so much ride height that I'm worried about, as it is the amount that the car "dips" when it goes over a bump. With the crown we have on our roads up here, it's just enough to make contact with the exhaust where the pipes pass under the diff. So, a slightly stiffer spring should take care of that. I haven't decided whether I will go with the stock 9-leaf, or the stiffer 7-leaf. I'm thinking a new 9-leaf may be enough stiffer than my worn 9-leaf to take care of the problem, but then again, while I'm under there...

One question, though: how am I supposed to tighten and torque the bolts once the car is on the ground? There ain't much room under there...

Joe

 

[chevyaddict]

We completely rebuilt our rear end unit and put a new spring in the car while it was all apart. It wasn't easy but wasn't difficult either. The big thing is afterward the car sat waaayyy too high in the back - so I would suggest getting those lowering bolts at the same time you get the spring - unless you like the car looking like a stink bug. :Silly

 

[racingundertaker]

Sometimes, just replacing the rubber "donuts" will restore some of the ride height. They can be bought cheaply. Be VERY careful when you let the spring down. It will literally break your arm if it flies loose.

I wrap the spring with a rag, then put a big vice grip over the rag. I position this toward the end of the spring. I then put my floor jack under the end of the spring, using my vice grip as a "stop point". I carefully remove the bolts, then let the spring down slowly with the floor jack. Do this on both sides, then remove the 4 bolts in the center. Be careful with these bolts, as sometimes you'll find 2 longer...2 shorter bolts. If you replace them incorrectly, you can poke the end of the bolt into the diff housing and cause a leak. Don't ask me how I know this.

Also, when you re-install the spring, do not tighten or torque the 4 center bolts till the car is back on the ground with weight on the spring. If you tighten them before the weight is on the car, you run the risk of breaking one of the "ears" on the diff mount.

Hope this helps. Chuck

I was going to replace the spring on my car.....but as I went to loosen the four center mounting bolts I noticed that there was a crack up the side of one of the ears. What is the best way to fix this, just to get me through the rest of the summer? The rear is coming out of the car this fall. Any help..would be greatly appreciated.

Thanks.

 

[80convertible]

I was going to replace the spring on my car.....but as I went to loosen the four center mounting bolts I noticed that there was a crack up the side of one of the ears. What is the best way to fix this, just to get me through the rest of the summer? The rear is coming out of the car this fall. Any help..would be greatly appreciated.

Thanks.

You can pick up a new heavy duty cover from Muskegon Brake for just under $100.00. For that price I would not try to fix the broken ear. Besides, the other ear could have some stress fractures too. Not worth the safety of you and your passengers.

 

[80convertible]

Joe,

The spring will bow down and most likely hit the pipes when you pull it loose from the trailing arms.

Just jack up the car, support on the frame in front of the rear wheels. Put some liquid wrench on all the bolts and let them soak.

Remove the four bolts holding the spring to the diff, and the long bolts/studs at each end. You will want to support each end when you remove the long stud, then let it down slow, repeat on the other side. It will fall right out....less your exhaust situation.

To add to the above post, here is a thread with pics I posted removing the rear spring bolts. http://corvetteactioncenter.com/forums/showthread.php?t=71164