Radius Arm Bushing

Replace the front radius arm bushings on a 1992 Dodge Viper by removing the radius arm from the suspension cradle and pressing out the old bushings.

Warnings

Tools required

Parts

• Radius arm bushing (front) × 2 — Mopar 04782486AA or equivalent
• Radius arm bushing (rear) × 2 — Mopar 04782487AA or equivalent

Preparation

1. Park vehicle on level ground and apply parking brake
2. Place wheel chocks behind rear wheels
3. Loosen front wheel lug nuts while vehicle is on ground
4. Raise front of vehicle with floor jack at manufacturer-specified jacking point
5. Support vehicle with jack stands placed under front suspension cradle, ensuring vehicle is stable
6. Remove front wheels completely

Procedure

1. 1

   Access the radius arm fasteners
   Locate the radius arm on the lower front suspension. The radius arm runs longitudinally from the lower control arm area forward to the suspension cradle. Identify the front mounting bolt at the cradle and the rear mounting bolt at the lower control arm junction. Apply penetrating oil to both mounting bolt threads and allow to soak for 5-10 minutes.
2. 2

   Remove rear radius arm mounting bolt
   Using a socket and breaker bar, remove the rear radius arm mounting bolt that connects the arm to the lower control arm area. This bolt passes through the rear bushing. Support the radius arm with one hand as you remove the fastener to prevent it from dropping. Remove the bolt completely and set aside.
3. 3

   Remove front radius arm mounting bolt
   Remove the front radius arm mounting bolt that secures the arm to the suspension cradle. This bolt passes through the front bushing. The arm will now be free from the vehicle. Carefully lower the radius arm and remove it from the suspension area.
4. 4

   Inspect radius arm and bushings
   With the radius arm removed, inspect the arm for cracks, deformation, or damage. Check both bushing locations for torn rubber, separation from metal sleeves, or excessive play. Note the orientation of the existing bushings before removal, paying attention to any offset or directional characteristics of the bushing design.
5. 5

   Press out front bushing
   Position the radius arm in a hydraulic press with the front bushing bore accessible. Select an appropriately sized bushing removal tool or press adapter that contacts only the outer bushing shell, not the arm itself. Press the old front bushing out of the arm. If the bushing is seized, apply additional penetrating oil and allow to soak, then retry. Clean the bushing bore with a wire brush after removal.
6. 6

   Press out rear bushing
   Reposition the radius arm in the press to access the rear bushing bore. Using the same technique as the front bushing, press the old rear bushing out of the arm. Clean the rear bushing bore thoroughly with a wire brush, removing all rust, old rubber, and debris. Inspect the bore for damage or distortion.
7. 7

   Press in new front bushing
   Verify the new front bushing orientation matches the old bushing. Apply a light coating of soapy water or bushing installation lubricant to the outer shell of the new bushing (never use petroleum-based products on rubber). Position the bushing at the front bore opening. Using the press and an appropriately sized installation adapter that supports the entire outer edge of the bushing, press the new bushing into the arm until it is fully seated and flush with both sides of the bore.
8. 8

   Press in new rear bushing
   Repeat the installation process for the rear bushing. Verify orientation, apply soapy water or bushing lubricant to the outer shell, and press into the rear bore until fully seated. Ensure the bushing is centered in the bore and sits flush on both sides. Do not over-press, as this can damage the bushing or arm.
9. 9

   Reinstall radius arm to suspension cradle
   Position the radius arm back into the suspension with the front bushing aligned to the mounting point on the suspension cradle. Insert the front mounting bolt through the cradle and front bushing. Thread the bolt by hand but do not fully tighten yet. The arm should pivot freely on this bolt.
10. 10

    Install rear radius arm mounting bolt
    Align the rear of the radius arm to the lower control arm mounting point. Insert the rear mounting bolt through the arm and rear bushing. Thread by hand but do not fully tighten. Both mounting points should now be loosely installed, allowing the arm to move through its travel.
11. 11

    Torque radius arm mounting bolts
    With the vehicle still on jack stands and suspension at normal ride height position, torque the front radius arm mounting bolt to specification, then torque the rear mounting bolt to specification. The suspension should be at ride height or loaded to simulate ride height when final torquing is performed to prevent bushing wind-up.
    ⚠Torquing suspension bushings with the suspension hanging or at full droop will cause premature bushing failure due to pre-loading. Ensure suspension is at ride height.
12. 12

    Reinstall wheel and lower vehicle
    Reinstall the front wheel, threading all lug nuts by hand first. Tighten lug nuts in a star pattern with a torque wrench to 136 Nm (100 lb-ft). Repeat for the opposite side if both radius arms were serviced. Carefully raise the vehicle slightly with the floor jack, remove jack stands, and lower the vehicle to the ground.
    Torque spec

    Wheel Lug Nuts136 Nm (100 lb-ft)

Reassembly

1. Repeat entire procedure for opposite side radius arm if necessary
2. After lowering vehicle, re-torque wheel lug nuts to specification in star pattern
3. If both radius arms were replaced, verify suspension alignment appears symmetrical

Verification

• Test drive vehicle at low speed in a safe area, listening for clunks or unusual noises from front suspension
• Verify steering response is normal with no pulling to either side
• Perform a professional wheel alignment after radius arm bushing replacement, as suspension geometry has been disturbed
• Re-inspect all radius arm mounting bolts after 50-100 miles of driving to ensure they remain tight

More procedures for this vehicle