CAMPAIGN: HARMONIC DAMPER CTR. BOLT UNDER TORQUED. GMC Truck Jimmy

SUBJECT: HARMONIC DAMPER CENTER BOLT UNDER TORQUED

MODELS: 1996 S/T UTILITY VEHICLES BUILT AT MORAINE ASSEMBLY

Some 1996 S/T Utility vehicles built during a four-day period at the Moraine Assembly plant may have a harmonic damper center-attaching bolt that was under torqued. This bolt secures the harmonic damper onto the crankshaft and the accessory drive pulley, which is attached to the damper, to the engine crankshaft. If this bolt were to completely loosen, the harmonic damper press fit would begin to loosen. This loosening would likely manifest itself as accessory drive belt noise, soon followed by the drive belt coming off the pulley or breaking, which would cause a loss of drive to the engine accessories. Additionally, the loosening of the damper-pulley assembly would likely damage the crankshaft.

To correct this condition, dealers will bring the harmonic damper bolt up to the specified torque.

VEHICLES INVOLVED

Involved are CERTAIN 1996 S/T Utility vehicles built within the following VIN breakpoints:

Plant Year Model Code From Through ---- ----- ------ ----- ------- 1996 Jimmy 2 T2520775 T2521781

The specific vehicles involved in this campaign have been identified by Vehicle Identification Number (VIN) Computer Listings. These listings are furnished to all involved dealers with the campaign bulletin. Dealers should confirm vehicle eligibility through VISS (Vehicle Information Service System) or SERVICENET prior to beginning campaign repairs.

DEALER CAMPAIGN RESPONSIBILITY

All unsold vehicles in dealers' possession and subject to this campaign MUST be held and inspected/repaired per the service procedure of this campaign bulletin BEFORE owners take possession of these vehicles.

Dealers are to service all vehicles subject to this campaign at no charge to owners, regardless of mileage, age of vehicle, or ownership, from this time forward.

Owners of vehicles recently sold from your vehicle inventory are to be contacted by the dealer and arrangements made to make the required correction according to instructions contained in this bulletin.

In summary, whenever a vehicle subject to this campaign enters your vehicle inventory, or is in your dealership for service in the future, please take the steps necessary to be sure the campaign correction has been made before selling or releasing the vehicle.

If the name and address of the owner of an involved vehicle was unavailable to Pontiac-GMC Truck Division at the time of campaign initiation, the dealer must determine the owner's name and address from the dealership sales records. Please provide this information directly on the second copy of the listing next to the applicable VIN so that our records may be updated and the appropriate notification mailed to the owner. This second copy should then be submitted to the address listed below in the previously supplied yellow campaign envelopes.

Pontiac-GMC Truck Division General Motors Corporation 101 Union Street Plymouth, Michigan 48170

OWNER NOTIFICATION

Owners will be notified of this campaign on their vehicles by Pontiac-GMC Truck Division (see copy of owner letter included with this bulletin). A listing of owner names and addresses has been furnished to the involved dealers to enable dealers to follow up with owners involved in this campaign. This listing may contain owner names and addresses obtained from State Motor Vehicle Registration records. The use of such motor vehicle registration data for any other purpose is a violation of law in several states. Accordingly, you are urged to limit the use of this listing to this campaign.

SERVICE PROCEDURE

1. Raise vehicle.

2. If T-Utility, remove splash shield (6 - 15mm bolts). (Not necessary for S-Utility)

3. While holding one of the three pulley bolts (to prevent crankshaft movement), torque the crankshaft pulley center bolt (Figure 1) to 90 Nm.

4. If T-Utility, install splash shield (6 - 15mm bolts). (Not necessary for S-Utility)

5. Lower vehicle.

6. Install Campaign Identification Label.

PARTS INFORMATION

No parts are required for this campaign.

WARRANTY INFORMATION

Dealers should submit a warranty claim on each vehicle completed under this campaign.

Labor *Labor Description CC FC Op Hrs ----------- -- -- ----- ------

Jimmy 2WD- MA 96 V9913 0.2 Crankshaft Pulley Bolt Re-Torque

Jimmy 4WD- MA 96 V9914 0.3 Crankshaft Pulley Re-Torque

* Campaign Administrative Allowance, add 0.1 hours to the "Labor Hours".

CAMPAIGN IDENTIFICATION LABEL

Each vehicle corrected in accordance with the instructions outlined in this product campaign bulletin will require a "Campaign Identification Label." Each label provides a space to include the campaign number and five (5) digit dealer code of the dealer performing the campaign service. This information must be inserted with a typewriter or ball point pen. This label is to be used in conjunction with the clear protective plastic cover provided with the Campaign Identification Labels.

Each "Campaign Identification Label" is to be located on the radiator core support in an area which will be visible when the vehicle is brought in for periodic servicing by the owner.

Apply "Campaign Identification Label" only on a clean, dry surface.

Additional Campaign Identification Labels and covers are available in sheets of 49 by calling VISPAC, Incorporated at 1-800-269-5100 (Monday through Friday 8:00 AM to 4:30 PM EST).

ADMINISTRATIVE PROCEDURE

Procedures covering this campaign are outlined in Section IV of your dealership's "WINS Claims Processing Manual".

Dear GMC Truck Customer:

As a valued customer, your complete satisfaction with your GMC truck is our goal. In keeping with this goal, we want to let you know that we have discovered a problem that could affect your vehicle and we want to take care of it at no charge to you.

To be absolutely sure that your vehicle is to specifications, your GMC dealer will bring the harmonic damper bolt up to the specified torque.

Instructions for performing this service have been sent to your GMC dealer. Please contact your GMC dealer to arrange a service date as soon as possible. This procedure will take about 20 minutes to complete, but you should ask how much additional time your dealer will need to schedule and process your vehicle.

The enclosed postage paid owner reply card identifies your vehicle. Presentation of this card to your dealer will assist in making the necessary correction to your vehicle in the shortest possible time. If you have sold or traded your vehicle, please furnish us the complete name and address of the person you sold or traded your vehicle to and return the card to us.

We are sorry to cause you this inconvenience; however, we have taken this action in the interest of your continued satisfaction with our product.

Pontiac-GMC Division GENERAL MOTORS CORPORATION

Object Number: 79811 Size: FS

General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.