Replacing the rear control arms in a 63 to 82 Corvette is one project most people and repair shops want to avoid. Granted, it does take more than the average mechanical ability and some special tools, but it is not an impossible task to complete. As with any project, you will need the right parts and Zip Corvette Parts, 8067 Fast Lane, Mechanicsville, VA 23111, 800-962-9632, will be able to supply all of your needs. You will also need a shop manual and an assembly manual for your year Corvette. These two books are invaluable whenever you are doing any type of repair.
The Sweepstakes 78 Corvette needed the rear control arms replaced since the bushings were worn and one control arm had a damaged bearing. We also replaced the strut rods and rear spring mounts while we were at it to insure a like-new ride and handling. Follow along as we complete the second phase of reconditioning our Sweepstakes 78 Corvette by replacing the rear control arms.
Click on the images for expanded views – it’s much easier on the eyes.
01: These are all of the items that Zip supplied for the rebuild: Complete control arms, strut rods, strut rod hardware, U-joints and hardware for the half shafts, rear spring mounts, shock absorbers and rubber bumpers. You will also need a shop and assembly manuals, hydraulic jack, jack stands and a full set of hand tools. A friend to help is also not a bad idea.
02: Place the car securely on jack stands and start by removing the wheels. Use penetrating oil on all of the brake hose and line connections. Use a line wrench to disconnect the brake caliper line from the rubber brake hose. Remove the caliper bolts and remove the caliper. Disconnect the emergency brake cable. The flexible brake hose can be removed from the control arm bracket. Remember to put a container under the brake hose to catch the fluid as it drains or use a pair of small vise grips to pinch off the brake hose so that it will not drain.
03: To remove the rear spring end mount, place a “C” clamp 9″ to 12″ from the end of the spring. Place a wooden 2″x4″ on the jack pad and rest it up against the “C” clamp. The “C” clamp will act as a stop so that the jack will not slip inboard. Raise the jack until the entire load is off the spring. Remove the cotter key, then the nut, bolt and cushions from the spring and control arm. When the bolt and cushions are removed, slowly release the tension on the spring.
04: Spread open the tabs on the French locks (If they are still present) and remove the half shaft to spindle bolts.
05: Loosen and remove the shock from its lower mount. Remove the strut rod shaft retaining bolt. The strut rod shaft can now be removed by pulling it towards the front of the vehicle. These shafts sometimes will be seized in the mount and will have to be driven out. Use a brass hammer or brass drift to tap the mount out of the spindle support. If your strut rod shaft is damaged, can supply a new one. NOTE: When the shock and strut rod is removed, the control arm will want to drop. You may want to put the jack under the arm to keep it from falling.
06: Before you remove the control arm, count the number of shims on each side of the control arm. These shims will have to be re-installed to retain the correct rear end alignment
07: Pull out the cotter key and spin off the control arm mounting bolt nut. Now while supporting the control arm, tap the mounting bolt out of the control arm. When it is free, remove the control arm from the car.
08: Here you can clearly see the control arm shims and retaining key.
09: Disconnect and remove the shock absorbers.
10: Make an alignment mark on the strut rod cam bolt and corresponding mark on the bracket. This will help you to re-align the cam bolt in the same position when you re-install it. You can now remove the cam bolt and strut rod.
11: We are going to replace the U-joints in the half shafts so they now can be removed. Disconnect the U-joint straps on the rear end axle flange and carefully slide the half shafts out. Remember to mark the shafts for the right or left side.
12: Unbolt and remove the upper rubber bumper.
13: Before you remove the U-joints, mark the shaft so that you will know which end went towards the rear end and which went towards the control arm. Without this mark, you will not be able to tell one end of the shaft from the other with the U-joints removed.
14: Start the half shaft disassembly by removing the U-joint retaining clips.
15: Place the U-joint flange end in a vise. Support one end of the flange with a 1 1/4″ socket and use a 1/2″ socket or lug nut to push the U-joint cap into the flange. This will push the opposite U-joint cup into the socket. When the cup is removed, press the opposite cap out by pressing the U-joint shaft against the remaining cap. Do this to remove all of the U-joints.
16: Start the re-assembly by using emery cloth to clean each area on the flange where the U-joint cups are pressed into place. Place one cap in the half shaft flange making sure it is centered in the flange opening. Keep the U-joint centered in the cup and slowly press the cup into the flange. Push the cup and U-joint in until the shaft of the U-joint on the opposite end is centered in the opposite flange. Now center the cup on this end and slowly push it into place in the flange and over the U-joint shaft. NOTE: It is very important that you keep the U-joint centered in the cup during installation. This will keep the needle bearings aligned. If one of the bearings falls into the bottom of the cup, you will not be able to fully install the cups or clips. Can you say “Start Over?”.
17: Use a lug nut or 1/2″ socket to push one cup into the flange so that the retaining clips can be installed. Install and seat the clip. Now place the lug nut on the opposite side and push this cup in so that the retaining clip can be installed. Make sure that the U-joint is not bound in the flange. It should move without binding up.
18: With the cup retaining clips installed, use a flat chisel to fully seat each clip into its groove.
19: If your U-joints have grease fittings, make sure that each fitting on each U-joint faces the center of the shaft. This will make greasing them much easier when the shafts are installed.
20: Before you re-install the half shaft, wrap masking tape around the rear end flange U-joint caps. Nothing is worse than to have a cap fall off and needle bearings rolling around on the floor.
21: Start by re-installing the half shafts. After they are installed, grease them while they are easy to get to.
22: Remove the spindle flange from the old control arms and clean it thoroughly. Check it for damage of worn splines. Install it on the new control arm and torque it to specifications.
23: Remove the control arm shims, keeping the inner and outer shims separate. Clean each shim using a wire brush and then measure the thickness of each respective set. Zip can supply packages of new shims that will allow you to re-shim each control arm.
24: Slide the new control arm into the mount. Then slide the retaining bolt into place and snug the nut. The inner and outer shims can now be installed. This sounds easier than it is. Once you have one set started, tap it in along side the control arm. The other set can be installed and tap those in. Remember, you will have to have each set aligned so that the retaining pin can be placed through all of the shims. NOTE: It is a good idea to use a jack to help support the control arm during installation.
25: Slip the retaining pin through all of the shims and spread the end. Torque the control arm bolt to specs and install the cotter key.
26: Grease the strut rod bushing caps with white lithium grease.
27: Install the strut rod and cap into the bracket and install the cam bolt. Align the cam bolt mark with the mark on the bracket and snug into place. DO NOT torque to specs.
28: Align the strut rod shaft and strut rod in the spindle support. Tap it into the spindle support. Install the strut rod shaft retaining bolt and torque to specs. Remember to install the cotter key. Notice that we are using a hydraulic jack to help support the control arm.
29: Install the half shaft to the spindle flange. Remember to bend the French lock tabs down onto the bolts after they have been torqued. The shock can be re-installed.
30: Place the “C” clamp, wood 2″x4″ and jack just as you did when you removed the spring mounting bolts. Jack the spring up so that you can install the bolt, washer and cushions onto the rear spring and control arm. When they are mounted, torque them to specs. Now slowly release the pressure on the spring. Install the cotter key. Remember, the bolt head is at the top and the curve of each washer faces the spring.
31: Re-connect the emergency brake cable and the flexible brake hose to the control arm.
32: Install the rotor onto the axle flange. It is very important to align this access hole with the hole in the axle flange. This hole allows access to the emergency brake shoe adjustment. If it is not aligned, you cannot adjust the emergency brake shoes without pulling the caliper. You will only need to do this one time to remember what a hassle it is to correct once you are done.
33: Install the rubber suspension bumper.
34: The caliper and steel brake line can now be re-installed and the brake system bled. Also check and adjust the emergency brake. Make sure all of the control arm bolts have been torqued and cotter keys installed where necessary. Place the car on the ground and roll it back and forth a few times. Now torque the strut rod cam bolts to specs. After you are finished, your first stop should be your favorite Corvette alignment shop to have the rear end alignment checked. After this is done, you are ready for miles and miles of trouble-free driving. Zip also provides installation service if you still feel the need to leave this job to a professional.
1963-1982 Corvette Trailing Arm, Strut Rod & Spring Mount Replacement
Source: Zip Corvette Parts
8067 Fast Lane | Mechanicsville, VA 23111 | (800) 962-9632
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