This item will fit 1984-1996 C4s.
I changed this due to traction issues and control issues during hard acceleration. Upon initial inspection I discovered the factory rod alignment/adjustment bolts were loose again. The factory design is difficult to keep locked down as indicated after several alignments during my 15 years of ownership.
The item installed was Corvette Central’s #584114. This is the same item as Mid America Motorworks’ 602-900. It came with the brace hardware and basic instructions. You will need to reuse the bolts from the spindle end. Once you perform this task, you will need an alignment.
Replacement is straight forward with a basic skill level required. This job can easily be performed on a set of tall jack stands in a driveway or garage. The overall time to perform the replacement was 2-3 hours including clean up. General shop safety rules apply and pay attention to breaking 100+ pounds of torque loose… Sometimes it breaks away quickly with little warning and there are a lot of things to smash your fingers on in this area.
Tools needed: ½” drive tools due to size and torque requirements of bolts. You’ll need ¾” to 1 1/8” box end and sockets to remove the stock hardware and install the new parts. I’d suggest a large hammer, safety goggles, tape measure, long breaker bar, torque wrench (50-160 foot pounds), pry bar and something to help align the bolt holes on the spindle to the new rod.
Getting started: I tried to perform the task with the wheels left on, but you’ll want to remove them for clearance and ease of access.
Prior to removing any hardware you’ll need to take some measurements. This is required to return the alignment close enough to drive. I chose to measure from the brace where the rods connect on the rear end to the spindles. Doesn’t matter where you measure, just that you measure so you can return the suspension close to previous measurements. Also while you are there, mark the spindle ends in some manner. This will be a quick reminder on which end goes where when you match the new rods to the factory rods.
Once you remove the hardware, the factory rods may need a little prying to remove if they have been on for some time. You can also use your floor jack to raise the spindles and reduce the stress on the spindle to help them drop out. Remember, you’ll need to reuse the spindle bolts, nuts and washers so don’t mess up the threads taking them out.
Now is a good time to look at the rear end braces, check for cracks and make sure the factory welds on the little channels on the braces are intact.
The directions provided tell you to measure from center of the factory rod’s bolt holes to get the measurement for the new rods. A better method is to align the new rods next to the old one and twist the center until you can slide the hardware through the bolts on the old and new piece. This will also ensure you get the rod ends at the right angles.
If they are at the right angle, the bolts on each end will slide easily into place.
Incorrect end matching (below)
Correct end matching (below)
Once they are at the correct length and you have verified the ends have the same number of threads protruding, lock down the jam nuts on the rod ends. You are ready to install them.
Installation: I recommend installing the rod end into the rear end brace first. It is easier to get the leverage needed for installation on the outer ends. You may need to jack up the spindles enough to make the install easier. Make sure to install the rear end rod end’s hardware as directed in the picture included with the rods. Also don’t torque anything down until you get all the hardware installed. This makes it significantly easier to twist the rods into place.
After you have installed the hardware it’s time to adjust the rods to the measurements you took when you started. Make sure to lock the jam nuts down again once you are done. Follow the torqueing specification on the following pages from the FSM.
CAUTION:The Chevy service manual calls for torque values on the spindle nuts to 107 foot pounds and the rear end bolts to 184. DO NOT torque the supplied rear end brace bolts to this torque—you will strip the threads!! The engineer’s handbook recommends 53-73 foot pounds for a grade 5, ½”-20 size bolt.
Double check everything and you are finished. Don’t forget the alignment.