GM Service Manual Online
For 1990-2009 cars only

Refer to General Description for information on conditions resulting from improper installation or frame insulators. Removing any one frame insulator requires loosening the adjacent frame insulators in order to permit the frame to separate from the body.

Replace the insulators carefully in order to prevent damaging the steering hoses and the brake pipes.

If the frame insulator bolt does not screw in smoothly, run a tap through the cage in the body in order to remove the foreign material. Ensure that the tap does not punch through the underbody. Position the insulator and the metal washer in order to prevent contact with the frame rail. Do not over tighten the insulator bolt. Overtightening the bolt may strip the cage nut.

Removal Procedure

    Caution: When you remove the body cushions, do NOT separate the frame from the body more than is necessary. Possible personal injury and damage to multiple parts may result if you do not follow the guides outlined below:

       • Intermediate steering shaft--Do not allow the shaft to extend more than 25 mm (1 in).
       • Fuel tank filler hose--Do not stretch the hose excessively.
       • Tail/Turn signal lamp wiring/rear lamps junction block--Leave slack in the wires.
       • Park brake cable--Leave slack in the cable.
       • Body ground straps--Leave slack in the wire.


    Object Number: 658414  Size: SH

    Important: Perform the procedure exactly as specified, regardless of whether you will replace all of the insulators or only one of the insulators.

  1. Raise the vehicle using a frame contact hoist. Refer to Lifting and Jacking the Vehicle in General Information.
  2. Support the frame (4) near the frame insulators being serviced using a pair of suitable tripod jackstands.
  3. Remove the bolts (7) and the retainers (6) from the insulators (5).
  4. Carefully lower the tripod jacks in order to lower the frame for insulator access.
  5. Pry the spacer (2) in order to remove the upper retainer (1) and spacer (2) first.
  6. Discard the retainer (1).
  7. Remove the insulators (3).
  8. Remove the lower insulators (5) and retainers (6) second.

Installation Procedure


    Object Number: 658414  Size: SH
  1. Install the following components:
  2. • The lower insulators (5)
    • The retainers (6)

    Important: Do not lubricate the lower frame insulator prior to installing the insulator into the frame.

  3. Press the lower insulators evenly into the frame dry.
  4. Slightly lubricate the lower outer edge only of the upper spacer (2) prior to installation.
  5. Position the insulator (3) and the upper spacer (2) to the frame.
  6. Using a (2 X 4 in) block of wood between the upper spacer (1) and the body, press the top spacer (2) into the lower insulator (5).
  7. Remove the block of wood.
  8. Repeat steps 1 thru 6 for additional insulators.
  9. Using 203 mm (8 in) long x 16 mm (0.63 in) dowel pins in the right and left rear frame alignment holes, align the engine frame to the body.
  10. Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

  11. Install the bolts (7).
  12. Tighten
    Tighten the insulator bolts (7) to 98 N·m (72 lb ft).

  13. Raise the supported vehicle.
  14. Remove the suitable tripod jackstands.
  15. Lower the vehicle.