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Makes 🢒 GMC_Truck 🢒 2004 🢒 GMC T-Series Medium Duty Truck F6/F7/F8 🢒 Bulletins 🢒 Knock/Clunk Noise From Cab Floorboard Area While Driving on Uneven Surface (Install shims Between Front Passenger Side Cab TiltMount and Frame)

Knock/Clunk Noise From Cab Floorboard Area While Driving on Uneven Surface (Install shims Between Front Passenger Side Cab TiltMount and Frame)

Subject:Knock/Clunk Noise from Cab Floorboard Area While Driving on Uneven Surface (Install Shims Between Front Passenger Side Cab Tilt Mount and Frame)

Models:2004 Chevrolet F-Model, T-Series Medium Duty Tilt Cab
2004 GMC F-Model, T-Series Medium Duty Tilt Cab
2004 Isuzu F-Model, T-Series Commercial Models
 
EXCEPT
2004 Chevrolet WT5500 Series Models
2004 GMC WT5500 Series Models
2004 Isuzu FRR Commercial Models


Condition

Some customers may comment on a knock or clunk noise/feel from the cab front floorboard area. This condition is more noticeable while driving on uneven surfaces. This noise is very loud and sharp. The noise/feel appears to be concentrated on the passenger side floorboard area, although it is felt on the driver's side.

Cause

The cab mount may be grounding out on the frame or cab.

Correction

Install shims between the front passenger side cab tilt mount and the frame using the following procedure. This procedure does not apply to the driver side cab tilt mount.

  1. Open the hood.
  2. Remove the grille. Refer to Grille Replacement (SI Document ID #228261).
  3. Remove the RH headlamp assemblies and bezel. Refer to Headlamp Replacement (SI Document ID #214552).

    4. Object Number: 1545443 Size: SH
  4. Loosen the three bolts from the frame side of the mount but DO NOT remove. Refer to the above illustration.
  5. Loosen the rear top mount to frame bolt but DO NOT remove.

    6. Object Number: 1545444 Size: SH
  6. Loosen the front top mount to frame bolt enough to let the mount open the gap to its maximum opening. The arrow in the illustration points to the gap that opened up.
  7. Take an approximate measurement of the gap and record opening between the mount and frame rail.

    8. Object Number: 1545445 Size: MF

    Important: Use washer type shim instead of open ended shim to prevent the shim from falling out.

  8. Build the necessary amount of washers (shims) to fill the gap between the mount and the top of the rail as shown above.
  9. Tighten the front top mount bolt, through the washers, and the rear top mount bolt.

    10. Tighten
    Tighten the front and rear top mount bolts to 185 N·m (136 lb ft).

  10. Tighten the three side mount to frame bolts.

    11. Tighten
    Tighten the three bolts to 185 N·m (136 lb ft).

  11. Install the RH headlamp bezel and headlamp assemblies. Refer to Headlamp Replacement (SI Document ID #214552).
  12. Install the grille. Refer to Grille Replacement (SI Document ID #228261).
  13. Close the hood.
  14. Verify that the condition has been corrected.

Warranty Information

For vehicles repaired under warranty, use:

Labor Operation

Description

Labor Time

E9419

Shim, Cab Front Mounting - Replace

0.5 hr