Rear Suspension Service

Complete inspection, lubrication, and replacement of rear suspension components including trailing arms, control arms, shocks, and transverse leaf spring on the 1966 Corvette independent rear suspension system.

Warnings

Tools required

Parts

• Rear shock absorbers × 2 — Use OEM specification or Monroe equivalent
• Lower control arm bushings × 4 — Use OEM specification
• Trailing arm bushings × 4 — Use OEM specification
• Sway bar end link bushings × 4 — Use OEM specification
• Transverse leaf spring × 1 — Use OEM specification
• Chassis grease (NLGI Grade 2) × 1 — Standard chassis grease

Fluids

• 75W-90 GL-5 Gear Oil — 2 qt

Preparation

1. Park vehicle on level concrete surface and engage parking brake.
2. Place wheel chocks at front wheels.
3. Loosen rear wheel lug nuts while vehicle is on ground.
4. Raise rear of vehicle and support on jack stands at frame rails behind rear wheels. Ensure adequate working clearance.
5. Remove both rear wheels.
6. Apply penetrating oil to all suspension fasteners and allow to soak for 15-20 minutes.
7. Place drain pan under differential and remove drain plug. Drain approximately 2 quarts of gear oil completely.
8. Disconnect rear brake calipers and secure to frame with wire. Do not allow calipers to hang by brake hoses.
9. Mark driveshaft-to-differential flange orientation for reassembly.

Procedure

1. 1

   Remove driveshaft
   Remove the 4 bolts securing the driveshaft universal joint flange to the differential pinion flange. Support the driveshaft and slide it rearward out of the transmission. Install a transmission plug or wrap the tailshaft in plastic to prevent fluid loss. Secure driveshaft away from work area.
2. 2

   Disconnect sway bar end links
   Remove the nuts securing both sway bar end links to the lower control arms. Note the orientation of washers and bushings for reassembly. The sway bar will remain attached to the frame.
   Torque spec

   Sway Bar End Link Nuts50 Nm (37 lb-ft)
3. 3

   Remove shock absorbers
   Remove the lower shock mounting bolt from each shock absorber where it attaches to the lower control arm or strut rod bracket. Remove the upper shock mounting hardware from inside the body (accessible through trunk). Remove both shock absorbers from the vehicle.
   Torque spec

   Shock Lower Bolt70 Nm (52 lb-ft)
4. 4

   Support differential carrier assembly
   Position a hydraulic transmission jack or equivalent under the differential carrier assembly. Raise jack until it just contacts the carrier and securely supports the weight. The carrier assembly weighs approximately 150 pounds and must be properly supported before disconnecting mounting points.
5. 5

   Disconnect axle halfshafts
   Remove the 4 bolts at each inboard CV joint connecting the halfshafts to the differential side gears. Support the halfshafts and allow them to hang from the outboard wheel hub or secure to the frame with wire. Do not allow the halfshafts to hang unsupported as this can damage the CV joints or wheel bearings.
6. 6

   Remove trailing arm frame bolts
   Locate the forward mounting bolts where each trailing arm (also called torque arm or strut rod) attaches to the frame brackets. Remove the 2 bolts securing each trailing arm to the frame, one per side. Leave the rear attachment at the carrier assembly connected for now.
   Torque spec

   Trailing Arm Bolts120 Nm (88 lb-ft)
7. 7

   Remove lower control arm frame bolts
   Remove the forward mounting bolt on each lower control arm where it attaches to the frame bracket near the differential nose. Remove 1 bolt per side. The rear of the control arms remain attached to the carrier assembly.
   Torque spec

   Lower Control Arm Bolts90 Nm (66 lb-ft)
8. 8

   Compress and disconnect transverse leaf spring
   Install a proper spring compressor tool on the single transverse leaf spring mounted to the differential carrier. Compress the spring slowly and evenly to relieve tension. Once compressed, remove the 2 bolts securing the spring center mount to the top of the differential carrier. Carefully remove the spring with compressor still installed and set aside in a safe area away from the work zone.
9. 9

   Lower and remove carrier assembly
   With all mounting points disconnected and the carrier supported on the jack, carefully lower the entire rear suspension carrier assembly (differential, trailing arms, lower control arms, and spindle assemblies all as one unit) away from the vehicle. Guide the assembly down and roll it out from under the vehicle. This assembly weighs approximately 150 pounds.
10. 10

    Inspect and service components
    With the carrier assembly removed, thoroughly inspect all bushings, bearings, and mounting points. Check lower control arm bushings at both frame and carrier ends for cracking or deterioration. Inspect trailing arm bushings at both ends. Check spindle support bearings for play or roughness. Examine the transverse spring mounting pads and center bolt hole for cracks. Clean all mounting surfaces with a wire brush and solvent. Replace any worn bushings by pressing out old bushings and pressing in new ones using appropriate driver tools.
11. 11

    Service or replace transverse leaf spring
    Inspect the transverse leaf spring for cracks, broken leaves, or sagging. If serviceable, clean mounting surfaces and apply a thin coat of anti-seize to center mounting bolt. If replacement is required, carefully release the spring compressor on the old spring in a controlled manner, then install compressor on new spring and compress to installation position. Lubricate spring eye bushings with chassis grease.
12. 12

    Reinstall carrier assembly at ride height
    Position the carrier assembly on the jack and carefully raise it into position under the vehicle. Install the compressed transverse leaf spring to the top of the carrier with the 2 center mounting bolts, but do not fully tighten yet. Guide the trailing arm forward mounts and lower control arm forward mounts into their frame brackets and install bolts finger-tight only. Reconnect the halfshaft inboard CV joints to the differential with 4 bolts each side and torque to specification. Use the transmission jack to adjust carrier height so suspension is at normal ride height (simulate vehicle weight). With suspension at ride height, torque trailing arm bolts to 120 Nm (88 lb-ft) and lower control arm bolts to 90 Nm (66 lb-ft). This is critical for proper bushing life.
    Torque spec

    Trailing Arm Bolts120 Nm (88 lb-ft)

    Lower Control Arm Bolts90 Nm (66 lb-ft)
13. 13

    Install shock absorbers and sway bar links
    Install new or serviced shock absorbers by securing the upper mount inside the body compartment first, then installing the lower mounting bolt through the control arm or strut bracket. Torque lower shock bolts to 70 Nm (52 lb-ft). Reconnect the sway bar end links to the lower control arms with bushings and washers in correct orientation. Torque end link nuts to 50 Nm (37 lb-ft).
    Torque spec

    Shock Lower Bolt70 Nm (52 lb-ft)

    Sway Bar End Link Nuts50 Nm (37 lb-ft)
14. 14

    Complete driveline and brake reconnection
    Align the driveshaft universal joint flange with the differential pinion flange using the alignment marks made during disassembly. Install the 4 flange bolts and torque to specification. Reconnect the brake calipers to their mounting brackets. Bleed the brake system if any brake lines were disconnected. Install the differential drain plug with a new crush washer and refill with 2.0 quarts of 75W-90 GL-5 gear oil through the fill plug.
15. 15

    Final inspection and test
    Remove the jack from under the carrier. Install both rear wheels and torque lug nuts to specification in a star pattern. Lower the vehicle to the ground. Bounce each rear corner of the vehicle several times to settle the suspension. Re-check all fastener torques, particularly the trailing arm and lower control arm bolts. Inspect for any fluid leaks at the differential. Test drive the vehicle at low speed in a safe area, checking for unusual noises, vibration, or handling issues. Verify proper brake operation before returning to service.

Reassembly

1. All suspension control arm fasteners (trailing arms and lower control arms) must be torqued to specification with the vehicle at ride height or with the suspension loaded to simulate ride height.
2. Ensure the transverse leaf spring is properly centered on the differential carrier before releasing spring compressor tension.
3. Bleed brake system if any hydraulic lines were opened during the procedure.
4. Verify differential is filled to proper level with 2.0 quarts of 75W-90 GL-5 gear oil.

Verification

• Test drive vehicle and verify smooth operation with no clunks, vibrations, or unusual handling characteristics.
• Perform visual inspection under vehicle for any fluid leaks from differential or brake system.
• Verify all suspension fasteners are properly torqued and show no signs of loosening.
• Check that brake pedal feels firm and brakes operate normally with no pulling to either side.
• Confirm shock absorbers are functioning by bouncing each rear corner - vehicle should return to rest without excessive oscillation.
• Verify wheel alignment is within specification - have alignment checked by qualified technician if vehicle pulls or tires show uneven wear.

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