Subframe Bushing

This procedure replaces worn subframe bushings on the 1992 Dodge Viper's tubular steel subframe, improving suspension geometry and handling precision.

Warnings

Tools required

Parts

• Subframe bushing set (front and rear) × 1 — Use OEM specification
• Subframe mounting bolts (if corroded) × 4 — Use OEM specification

Preparation

1. Park vehicle on level, solid surface and engage parking brake.
2. Chock rear wheels securely.
3. Loosen front wheel lug nuts while vehicle is on ground.
4. Raise front of vehicle and support on jack stands placed at manufacturer-specified jacking points on the body/frame rails, not on the subframe itself.
5. Remove both front wheels.
6. Apply penetrating oil to all subframe mounting bolts and allow to soak for 15-30 minutes.
7. Position hydraulic transmission jack or subframe support stand under the center of the subframe, adjusted to just contact but not support weight yet.

Procedure

1. 1

   Disconnect steering intermediate shaft
   Locate the steering intermediate shaft U-joint connection at the steering rack input shaft. Mark the alignment of the shaft to the rack pinion for reassembly reference. Remove the steering shaft pinch bolt and separate the intermediate shaft from the steering rack. Secure the steering shaft up and out of the way with mechanics wire to prevent damage during subframe lowering.
2. 2

   Disconnect front sway bar links
   Locate the front sway bar end links connecting the sway bar to the lower control arms on both sides. Using an Allen key to hold the link shaft from rotating, remove the upper sway bar link nuts on both sides. The sway bar will remain attached to the subframe and will lower with it.
   Torque spec

   Sway Bar Link61 Nm (45 lb-ft)
3. 3

   Support engine and transmission
   Verify in service documentation how the engine and transmission are supported relative to the subframe before proceeding. Do not assume the powertrain is carried by the removable subframe. Place a jack stand with a wood block under the engine oil pan to support engine weight, or use an engine support bar across the shock towers, and support the powertrain independently. Place a jack stand with a wood block under the engine oil pan to support engine weight, or use an engine support bar across the shock towers. Adjust to just contact and support the engine/transmission assembly weight before subframe removal. Do not lift the engine, only support its weight.
4. 4

   Disconnect brake lines and ABS sensors
   Locate brake line brackets and hard lines attached to the subframe. Remove any brake line retaining clips or brackets securing brake lines to the subframe. Ensure sufficient slack exists in brake lines to allow subframe to lower approximately 6-8 inches without stretching lines. If any wheel speed or suspension sensor wiring is routed along the subframe, verify actual equipment on this vehicle before proceeding; note the 1992 Viper was not factory-equipped with ABS. Disconnect or unbolt any harness brackets present to provide slack. Do not disconnect brake lines at fittings unless absolutely necessary. Note: Disconnect brake line brackets and wiring harnesses
   ⚠If brake lines must be disconnected, the brake system will require bleeding after reassembly. Cap all open fittings immediately to prevent fluid loss and contamination.
5. 5

   Mark subframe position
   Before removing subframe bolts, use a paint marker or scribe to mark the exact position of the subframe relative to the chassis mounting points. Mark around the subframe mounting flanges at all four corners. These alignment marks are critical for proper reassembly and maintaining suspension geometry.
6. 6

   Remove subframe mounting bolts
   Locate the four primary subframe mounting bolts connecting the subframe to the chassis. These are typically located at the four corners of the subframe assembly. Raise the hydraulic transmission jack to firmly support the subframe weight. Loosen all four subframe mounting bolts approximately 3-4 turns each but do not remove completely. Verify the transmission jack is securely supporting the subframe, then remove all four mounting bolts completely. Carefully and slowly lower the subframe approximately 6-8 inches or until the bushings are accessible for removal. Do not lower beyond what is necessary.
   ⚠️The subframe assembly with attached suspension components weighs approximately 150-200 lbs. Lower slowly and maintain control at all times. Have an assistant help guide the assembly if possible.
7. 7

   Inspect subframe and bushing condition
   With the subframe lowered, inspect all mounting points for damage, cracks, or corrosion. Examine the existing bushings for deterioration patterns - cracks, voids, oil contamination, or compression set indicate replacement is necessary. Note the orientation of existing bushings including any voids, offset positioning, or directional features before removal.
8. 8

   Remove old subframe bushings
   The subframe bushings are press-fit into the subframe mounting brackets. Using a bushing press kit with appropriately sized receivers and drivers, press out the old bushings from the subframe mounting locations. If no press is available, carefully use a large C-clamp with sockets as drivers/receivers, or cut the old bushing rubber away and collapse the outer sleeve to remove. Clean all bushing bores thoroughly with a wire brush, removing all rust, old rubber debris, and corrosion. Inspect bushing bore for damage or cracks.
   ⚠Do not use heat or torches to remove bushings as this can damage the subframe material and alter its structural properties.
9. 9

   Install new subframe bushings
   Compare new bushings to old bushings removed in the previous step to verify correct replacement parts and orientation. Note any voids, offset design, or directional markings on the new bushings. Apply a light coating of soapy water or approved bushing lubricant (never petroleum-based products on rubber bushings) to the outer sleeve of the new bushings. Using the bushing press with appropriate drivers and receivers, press the new bushings squarely into the subframe mounting bores until fully seated and flush with the mounting surface. Verify bushings are not cocked or partially seated - they must be fully bottomed in the bore.
   ⚠Do not use grease or oil to lubricate bushings during installation as petroleum products will degrade the rubber. Use only soapy water or manufacturer-approved bushing lubricant.
10. 10

    Raise and align subframe
    Apply anti-seize compound to the threads of the subframe mounting bolts (replacement bolts if originals are corroded, otherwise clean and reuse original bolts). With the transmission jack, carefully raise the subframe back into position, aligning it with the paint marks made during removal. Thread in all four subframe mounting bolts by hand to prevent cross-threading. Finger-tighten all bolts to draw the subframe into approximate position. Verify alignment marks match before proceeding.
11. 11

    Reconnect steering intermediate shaft
    Align the steering intermediate shaft U-joint with the steering rack input shaft, matching the alignment marks made during disassembly. Install the pinch bolt finger-tight. Verify the steering shaft rotates freely and is properly seated before final tightening. Torque the steering shaft pinch bolt to the exact specification listed in the vehicle service manual (verify value before final tightening).
12. 12

    Reconnect brake lines and sway bar links
    Reinstall all brake line brackets and clips to the subframe. Verify brake lines have no kinks, sharp bends, or tension. Reconnect the front sway bar end links to the lower control arms on both sides. Hold the link shaft with an Allen key and torque the upper nuts to specification.
    Torque spec

    Sway Bar Link61 Nm (45 lb-ft)
13. 13

    Install wheels and lower vehicle
    Reinstall both front wheels and thread lug nuts by hand. Lower the vehicle until the tires just contact the ground but the suspension is not yet fully loaded. Torque the wheel lug nuts in a star pattern to specification.
    Torque spec

    Wheel Lug Nuts136 Nm (100 lb-ft)
14. 14

    Final torque subframe bolts with vehicle weight on suspension
    Lower the vehicle completely so full vehicle weight is on the suspension and tires are supporting the vehicle on level ground. This is critical - subframe bushing bolts must be torqued with the suspension at normal ride height to prevent premature bushing failure. Working in a cross pattern, torque all four subframe mounting bolts to manufacturer specification. Torque all four subframe mounting bolts to the exact specification listed in the vehicle service manual (value must be verified in Viper service documentation before final tightening).
    ⚠Torquing subframe bolts with the suspension hanging or at full droop will preload the bushings incorrectly and cause rapid failure. Vehicle weight MUST be on the wheels.
15. 15

    Remove engine support and final checks
    Remove the jack stand or engine support bar used to support the engine during subframe removal. Verify all fasteners have been reinstalled and torqued. Check that no tools or hardware remain in the work area. Verify brake lines are secure and free from interference. Turn the steering wheel lock-to-lock while stationary to verify full steering travel with no binding or interference.

Reassembly

1. Reassembly is covered in the main procedure steps as this job requires specific sequencing for proper bushing installation.
2. Critical: All subframe mounting bolts must be torqued to final specification with vehicle weight on the suspension at normal ride height.
3. Verify steering intermediate shaft pinch bolt is properly torqued and shaft alignment marks are matched.

Verification

• Start engine and verify no fluid leaks from brake lines or power steering system.
• Test drive vehicle at low speed in a safe area and verify steering operates normally with no binding, unusual noises, or vibration.
• After test drive, re-check all subframe mounting bolt torque and wheel lug nut torque.
• Schedule a professional alignment within 50 miles of completing this repair as subframe removal will affect suspension geometry.
• Monitor for any unusual noises, vibrations, or handling changes over the first 100 miles of driving.

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