Can someone out there please give me some step by step instructions or point me to a website that can give me intructions on installing a new rear spring?
It looks pretty straighforward and easy but being a Corvette...I'm sure that like anything else on these cars, it's not nearly as easy as it looks.:eyerole
I'm most worried about centering the spring. My mechanical skills are limited, but I'm trying.
Thank You Very Much In Advance
The C4
rear spring is pretty easy..
Its centered on mounting blocks that are made onto the spring.
There is a process though...
Do a quick visual inspection of the rubber grommets on the end links to see if they need to be replaced. If so, get a set and have them there for the swap. If this is a differenr code spring, see if you can have some extra shims for the center mounts. All the springs have different shim size and order.
The car does not need to be lifted but its much easier if it is raised to create some working room underneath..
Jack up and support with jackstands on the frame. Removing rear wheels makes more room and allows more that can be seen.Lots of housework that can be done under there as well.
Pull cotter pin out of castle nut on both end link long bolts.
Loosen castle nut almost to the end of the bolt. The springs natural arc will try to follow the nut down on the bolt but the tension becomes minimal at the end.
Now, there are 2 center support mounts. Each has 2 bolts. Notice how well the center brackets fit against the carrier. This "fit" is via a set of
shims between the bracket and carrier with the spring sandwiched inbetween.
These brackets are aluminum and WILL crack very easily, so remove the bolts 1/2 turn at a time as long as there is tension, then do the other, and re-assemble the same way. Clean the pieces before assembly.
The exhaust MAY be in the way so look to see what wrenches it'll take to get to the bolts. Some can use a socket, others take an open end...
As the center bolts come out the whole spring lowers, so at some point you will feel thespring tension is all gone, then its safe to remove the end link castle nuts.
BEFORE you remove the 2 center mount brackets,
make note of the exact shim order and arrangement.
The replacement spring may or may not use the same number of shims, it may require more, so have some available. If the replacement spring is the same code as the original, the shim order will be the same and should fit the same. Different coded springs take a different order and thickness of shims. The shims come in various thickness also. This is a semi-precision fit.
When you reassemble, get the center bolts most of the way up, not tight, and then get the end link bolts thru and get the nut started.
If the spring is too stiff or too far down to get the long bolt thru, use a floor jack to lift the end up enough to get the castle nut on the long bolt. Be sure the grommets are on the right way. If the wheels are off, its easier to get the end link bolts started. The weight of the wheels sometimes becomes an issue when trying to lift the spring up and get the long bolt thru and a nut on there.
After both end links are started, gently tighten the center bracket bolts, back & forth until the bracket is snug against the carrier, but the shims have the springs rubber blocks pinched in place. Do not over tighten these 4 bolts....
33 lbs torque on center bolts.
I have done this with the Toe rods disconnected at the knuckle or attached. This is a great time to D/C the toe rods and check them. Loose toe rods, that are too loose, cause accidents if they seperate in the center socket while driving. Thats all that keeps the rear wheels in line with the chassis.
They are so stiff when new that they will hold some weight on the end, but as they wear they get loose and will not stay. If you can feel any looseness in the rod center socket or tie-rod end, REPLACE the assembly immediately. Rear toe rod failures are UGLY if they happen on the freeway. The rear end steers out of control and you have no say in the matter. Thats why its worth testing these rear toe rods annually. They are not rebuildable either.The outter ends can be replaced but the rods and center assembly are non servicable. That rod assembly is available from various after market stores in various types and levels of strength and performance. Rear toe rod end, to knuckle shaft/nut 37 lbs torque.
NOTE:
the end link castle nut does NOT need to be run all the way up on the long bolt. In fact, this is how the rear end ride height can be adjusted to a small degree. If you leave the nut down on the bolt, this allows the body to ride UP. Adjust both sides approx the same height and install new cotter pin in long bolt/castle nut.
If the nut is tightened all the way, this draws the body down. basically you are either allowing the full arc of the spring or flattening it, creating some pre-tension or pre-loading on the suspension. Even the placement of the shims can make a difference in the ride height, if they are over or under the spring. If the spring is allowed to have its full arc the body will ride higher. By tightening those end link nuts you are taking the arc out, thus lowering the body slightly.
Never allow degreasers or cleaners to come in contact with the composite spring. Certain chemicals will have a reaction with the resin that the spring is made with, causing them to fail within hours of contact. There is no warning sign, no physical reaction until it just breaks. There was a GM service bulletin regarding this, many yrs ago.
This is a 2-3 hr project with avg tools and skills. Most important is the correct assembly of the spring center mounts and shim order/spacing.
if you have access to a water hose with the wheels off and the car raised, and the spring OUT<--
Get some Eagle-1 cast wheel cleaner and spray the aluminum underside and frame, back of hubs, axle shafts....that stuff brings all the aluminum back to a NEW shine,. its a type of acid, so use caution.
This is one of the chemicals that will destroy the composite rear spring IF it gets on the spring. Thats why you only do this when the spring is out of the car and 30' away...Clean and assemble. Piece of cake..
Good luck, hope this helps.
PS
if you need shims before starting, most catalog stors online have them, so do all the salvage shops and vette shops.
S.T.W.
