Holes will need to be drilled into the frame to drop the provided U-Bolt in place. You should start the most forward hole, 1-5/8” from the welded in cross member located just behind the differential cross member. The next hole should be 3” behind the first hole. Continue to step 3.

The spindle will need to be slightly clearanced to clear the lower shock once at ride height. Grind around 5/8″ up from the bottom of the spindle.

See the mark on the spindle for the area to clearance. Only need to take about 1/6″ of material.

Install the shock inserts, then the 1/2″ lower onto the lower plate and torque to 60 ft/lbs. This will not be accessible once installed on the lower control arm.

You can install the sway bar end links now for ease of installing the lower bolt, or install after mounting the lower plate to the lower control arm. We installed the end links before mounting the plate.

To install the shock, the upper portion must go in first. Hold the spindle away from the frame to gain enough clearance for the shock clear the control arm and the lip on the frame.

The upper clevis is offset for spring clearance. Ensure that the offset is pushing the eyelet of the shock towards the outboard (wheel) side of the car.

To install the lower mount, by pressing down on the lower control arm while holding the spindle away from the frame. Install the top two retaining bolts as the one next to the end link is very tight.

Next, lift up on the control arm to reinstall the lower ball joint and tighten the lower mount bolts. Tighten the two top mount bolts, and torque to 35 ft/lbs followed by the one on the side by the sway bar mount. The fourth hole is optional but recommended for additional strength.

Tighten the upper clevis next. You’ll need a 10mm wrench to keep the clevis in place. The eccentric washer will need to have the thin side towards the outside of the car to maximize spring to frame clearance. Torque the M14 nut to 50 ft/lbs.

These bolts all take a 13mm socket or wrench.

Completed unit, ready for ride height adjustment.

Before installing the upper sway bar end link, you’ll want to set final ride height. Loosen the jam nut and spring collar to desired height. The shocks ship with the spring only hand tightened so the spring doesn’t rattle during shipping. This should be near factory ride height though.

The car will need to be rolled or driven a very short distance to get the suspension to settle. Typically 100-200 ft should be plenty. Adjust ride height as needed and settle the suspension each time.

After driving on a four post lift or up on ramps, install the upper sway bar end link. The suspension will need to have the full weight of the car to properly adjust the end links. Position the sway bar at the desired height and adjust the end links accordingly. Tighten down, align the car and you’ll be ready for a new riding and/or handling early model C4 Corvette.

Remove the carrier bearings, ring gear, plates and springs, then clutches.

Chuck the posi in a lathe and ensure it’s centered. Dial indicator is to make sure the unit is running true on the lathe before machining.

Standard ID on the posi is around 1.247″.

This will need to be opened up to a diameter of 1.295″ for the new axles with a step cut coming next.

Your posi should now have a bore of 1.295″ and a step that is 1.395″ on the outer edge of the bore that is .325″ deep. This allows the new side yokes to be pushed in far enough to install the 12 bolt c-clips during assembly of the differential.

Finally, sand or file the hard edges and clean the posi before re-assembling.

1. With the factory sway bar removed, install the rearward bolt on the thin part of the adapter bracket. Install both brackets hand tight.

2. Install the poly bushings on the sway bar making sure to lubricate the inside of the bushing very well.

3. Feed the sway bar through the cradle.

4. Place the forward most bolt in next. This bolt goes all the way to the frame. Make sure to place the provided washer between the gold bracket and the relocation bracket. This keeps the bushing bracket from pinching the sway bar bushings and limiting rotation.

5. Install the reward bushing bracket bolt. This image shows the washer that goes on top of the bushing brackets.

6. Torque down the 6 frame mount bolts until securely snug.

7. After the bushings are snug, grab the end of the sway bar and rotate the bar up and down. There should be some resistance to the bar. You want to make sure it doesn’t freely move up and down with little resistance or is overly hard to rotate the bar.

8. You’ll you need to remove the lower sway bar bushing in the control arm next. (instructions for this coming soon)

9. Install the aluminum lower sway bar bushings and the end links on the lower control arms only then bolt on your front wheels

10. Set the car down on ramps so you can adjust and install the upper bolt on the end links. The rearward most hole will be the softest setting and the inward most hole the stiffest. You may have to use the soft setting to clear the tie rod ends. Double check that all your bolts are tight and set the car on the ground.

11. Finally, turn the wheels full lock in each direction and check your endlink to tie rod end clearance. You may need to adjust the gold sway bar brackets to give your self more clearance at full lock.

Delrin Cross Member Bushings

When installing the Delrin differential cross member bushings, we recommend using a little bit of grease on the OD of the bushing. You will need a press or arbor press to install the bushings. Make sure the bushing goes in straight. You may need to take a die grinder to open up the ID of the cross member hole. This process may need to be done due to rust scaling and/or paint in the cross member. The bushing should never have “play” in it. If it does, the cross member holes are elongated and you should source a new one. 

In rare occasions we have found there is an air gap between the delrin bushing and the SG-47 plate. Install one large washer per side so the SG-47 plates no longer have an air gap.

SG-47 Reinforcement Plates

You have to have these style plates to retain the delrin bushings. If you do not have these plates, you’ll need to order the SG-54 kit or if you already purchased the SG-53 kit, you’ll need to order our SG-47 plates.

Install the studs after the differential cross member is installed. The coarse threads go into the frame. Install the aluminum disc/flat wash/lock washer & nut. Torque the nut to 30-35 ft/lbs or yeild. Recheck the torque after 50 miles or after the 1st event. If your kit came with all four nuts and washers like shown to the left, you’ll discard two nuts and two flat washers.

Pinion Bushing

Install these bushings as you would a factory bushing and torque to factory spec. We include an Upper Poly Bushing and a Delrin Lower Bushing. Torque to 70 ft/lbs.

left graphic: Orientation is set as would be in the car. The thick part of the bushing should go up into the frame mount. Make sure to check that your crossmember needs the washer between the bushing and the SG-47 plate

Front wheel bearings: The front wheel bearings on C2 and C3 Vettes can wear out due to factors such as lack of lubrication, contamination, and normal wear over time. Signs of worn front wheel bearings may include a grinding or humming noise from the front wheels, uneven tire wear, steering wheel vibration, pulsating or spongy brake pedal, uneven brake pad wear, or excessive play in the wheel when jacked up off the ground. If these symptoms are present, it is advisable to have the front wheel bearings inspected and potentially replaced.

Front wheel bearing hubs: The front hubs not the Corvette are prone to warpage like a rotor. The face of the hub, when clean, should have a run out of no more than .008 and we prefer less than .005. These low numbers are due to the fact the C2 and C3 Vettes have a fixed caliper versus a floating caliper like most standard late model Corvettes. If you are constantly bleeding the brakes for a spongy pedal and/or have uneven brake pad wear, you probably need to replace your hubs not just rebuild with new bearings.

Rear wheel bearings: The rear wheel bearings are also susceptible to wear and tear. Symptoms of worn rear wheel bearings are similar to those of the front bearings and may include noise that increase and decreases with speed along with play in the wheels. The rears tend to actually wear out faster than the fronts due to the OE manufacturing spec to produce cars at a production speeds. Parts to inspect when you find play in the rear wheels before replacing any parts include; the strut rod/camber rod bushings, t-arm bushings, half shaft u-joints and inner axle in and out play.

If the rest of the components are good, then it’s time for a rebuild. When rebuilding your own parts you must inspect all the components to ensure proper bearing life and brake pedal feel. The rear spindle has to be inspected for run out on the face of a clean spindle. This should be no higher than .005. The bearing surface areas should be inspected for excessive wear or if they have been machined down for a slip fit. The slip fit helps with install but is not the proper way and can lead to premature bearing failure. We’ve rebuilt many a bearing assembly that were fresh rebuilds to find they had overly worn or slip fit spindles. Finally an often over looked item are the caliper mounting brackets. They can be bent from the car bottoming out and/or pad knock from worn out bearings. For proper braking on a fixed caliper, these should be replaced if not spot on.

Rubber bushings are the most common type of bushing used in vehicle suspensions. They are inexpensive and provide a comfortable ride because of their ability to absorb shocks and vibrations. However, they tend to wear out relatively quickly and may deteriorate over time, especially if exposed to high temperatures or chemicals. We only have these available for 63-82 Corvettes.

Polyurethane bushings are an alternative to rubber bushings. They are stiffer and more durable than rubber, which improves handling and reduces flex in the suspension. Polyurethane bushings also last longer than rubber and are more resistant to wear and tear. However, they can be more expensive than rubber and may produce more slightly more road noise and vibration in the vehicle. We have these available for 63-96 Corvettes.

Delrin bushings are a type of thermoplastic bushing that is highly durable and resistant to wear and tear. They are much stiffer than rubber or polyurethane bushings, which improves handling and reduces flex in the suspension. Delrin bushings are also less susceptible to changes in temperature and are less likely to squeak or produce noise. However, they can be more expensive than both rubber and polyurethane bushings. These are available on our 63-82 front coilover kits and 1984-2019 Corvettes.

To determine which side is LH & RH, place the bearing support on a table with the outer bearing on the table and the legs facing you like shown above. The legs will have 2 holes for the shock mount to pass through. One is a 3/4 hole (D shaped hole), the other is a full circle. The side with a flat will determine if it’s a LH or RH bearing support. The side with the flat will be towards the back of the car.

1. Put the bearing support in a bench vice with the outer bearing facing you. The inboard side will have a silver dust shield on it.

2. Install the trailing arm with the 4 mounting studs pre-installed. Make sure the flat in the shock mount hole is towards the back of the t-arm.

3. Install the caliper mounting bracket. Be careful here b/c caliper
mounting brackets are LH & RH as well. The long flat should go
toward the front of the car. ***Pro Tip If you have a packing
peanut/small piece of cardboard/paper, put it in the divot on the
caliper mounting bracket and tape it in place with masking tape.
This will prevent the Parking Brake Side Pin from falling into the
hole which makes it difficult to install the side spring.

4. Install the backing plate with BOTH side pins. We recommend that you tape both on with masking tape or alike.

5. Install the 4 lock washers and nuts onto the 4 t-arm mounting
studs. Do not tighten

6. Install the parking brake anchor block with guide plate (wings up) and ½”-20 bolt.  Torque value is not critical here b/c there is no load on the bolt. If a value is needed, 60 ft/lbs is sufficient. Bend the 2 top tabs up to the side of the bolt. This prevents the bolt from loosening up.  ***Pro Tip Use an adjustable wrench and place it over the anchor block. Make sure the long flats on the anchor block are parallel to the ground if you will. As you tighten the anchor block bolt, the wrench will prevent the block from rotating.

7. Torque the 4 mounting stud nuts down. – 35 ft/lbs

8. Install the parking brake hardware and shoes. We like to put the star adjuster on the RH.

9. Remove the assembly from the bench vice and set it on top of the spindle. Once the spindle is in place, set the 2 pieces into a press. Place the spindle flange on top of the spindle and begin pressing the spindle into place. After a few pumps on the press, make sure the splines on the spindle flange are aligned with the splines on the spindle. Once that is aligned continue pressing the assembly together while rotating the assembly left to right until fully seated.

10. Remove the spindle flange and carefully remove the assembly from the press and place it back into the bench vise.

11. Install the rotor with lug nuts and aligning the parking brake hole in the spindle to the parking brake hole on the rotor. If the rotor does not have a parking brake hole, STOP and find the correct rotor. All 65-82 rear rotors will have a parking brake hole, front rotors will not.

12. Using a dial indicator with a magnetic base, place the indicator on the outer most edge of the friction surface. The rotor runout needs to be .005” or UNDER. If the runout is higher, you need to diagnose the problem and see if it’s the rotor or the spindle being used. If the spindle has a high run out and it’s already been pressed in, it needs to be removed and replaced. If it’s removed, new bearings are recommended since these bearings are a press fit and defeats the purpose of why you purchased a built assembly in the first place. If the runout is in the rotor, find the high spot and grind it out on the mating surface side.

13. Once rotor runout is completed, mark the spindle and rotor.

14. Install the spindle flange with washer and nut. Torque to 100 ft/lb. If the cotter pin hole doesn’t line up, GO TIGHTER.

15. The assembly should be complete and ready bolt into the car. We recommend removing the rotor for installation. It’s 20 lbs lighter without it on. Once the assembly is in the car, you can install the rotor by aligning the 2 marks you put on the spindle and rotor. Secure it with a lug nut until the tire is ready to go on.