CAMPAIGN: AUTOMATIC TRANS FLUID LEAK

SUBJECT: AUTOMATIC TRANSMISSION FLUID CONTAINMENT

MODELS: 1988-93 C/K (ALL MODELS) EQUIPPED WITH 5.OL, 5.7L, 7.4L ENGINES AND 4L60, 4L60-E AND 3L80 AUTOMATIC TRANSMISSIONS

The National Traffic and Motor Vehicle Safety Act, as amended, provides that each vehicle which is subject to a recall campaign of this type must be adequately repaired within a reasonable time after the owner has tendered it for repair. A failure to adequately repair within 60 days after tender of a vehicle is prima facie evidence of failure to repair within a reasonable time.

If the condition is not adequately repaired within a reasonable time, the owner may be entitled to an identical or reasonably equivalent vehicle at no charge, or to a refund of the purchase price less a reasonable allowance for depreciation.

To avoid having to provide these burdensome solutions, every effort must be made to promptly schedule appointments with owners and to repair their vehicles as soon as possible. As you will see in reading the attached copy of the letter which is being sent to owners, the owner is being instructed to contact the nearest GMC Truck Zone Office if the dealer does not remedy the condition within five days of the mutually agreed upon service date. If the condition is not remedied within a reasonable time, they are instructed how to contact the National Highway Traffic Safety Administration.

DEFECT INVOLVED

General Motors has determined that a defect which relates to motor vehicle safety exists in CERTAIN 1988-93 C/K Models equipped with 5.OL, 5.7L, 7.4L engines and 4L60, 4L60-E, and 3L80 automatic transmissions. The transmission fluid in these vehicles, as a result of unanticipated heat generation in the transmission, may be forced out of the vent tube. The vented transmission fluid may come in contact with the catalytic converter and ignition of the transmission fluid may result.

To prevent this condition from occurring, dealers are to install a longer transmission vent hose routed to the left side of the vehicle.

VEHICLES INVOLVED

Involved are the models built within the VIN breakpoints listed below.

Models Involved: --------------- -1988-93 C/K 1,2 model trucks equipped with 5.7L (LO5) engines and 4L60/4L60-E (MDB/M30) automatic transmission

-1988-93 C/K 2 model trucks equipped with 5.0L (LO3) engines and 4L60/4L60-E (MD8/M30) automatic transmission

-1988-90 C/K 2,3 model trucks equipped with 5.7L (L05) or 7.4L (L19) engines and 3L80 (M40) automatic transmission

VIN Breakpoints:

Model Plant From Through Year ----- ---- ------- ----- 1988-93 Ft. Wayne (Z) SOP PZ500481 1988 Janesville (J) SOP EOP 1992 1992 Oshawa (1) SOP P1502478 1988 Pontiac (E) SOP P3500573 1988

The specific vehicles involved in this campaign have been identified by Vehicle Identification Number 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) prior to beginning campaign repairs.

DEALER CAMPAIGN RESPONSIBILITY

All unsold new 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 new vehicle inventory with no owner information indicated on the dealer listing, are to be contacted by the dealer, and arrangements made to make the required correction according to the instructions contained in this bulletin. This could be done by mailing to such owners a copy of the owner letter accompanying this bulletin. Campaign follow-up cards should not be used for this purpose, since the owner may not as yet have received the notification letter.

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 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.

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 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. Inspect vehicle for presence of lock-seal dipstick (Figure 1) as installed in campaign 90-C-26, dated January, 1992. If this lock-seal dipstick is not present it should be obtained through GMSPPO to complete campaign 90-C-26.

2. Raise vehicle on hoist.

3. Inspect existing transmission vent tube (Figure 2) to be certain it is not plugged with dirt or debris and clean if necessary.

IMPORTANT

It is important that this vent tube is open. If this tube is plugged, premature transmission seal failure may occur.

4. Lube the inner diameter of the vent hose with a small amount of clean transmission fluid and install it over the existing vent tube until secure.

IMPORTANT

This vent hose is constructed of fuel line rated material. The use of any other type hose is discouraged as it may deteriorate in this application.

5. Locate the vent hose as shown in Figure 2 and secure it to the transmission wiring harness with the tie strap.

6. Install campaign identification label.

PARTS INFORMATION

Each dealer will receive from General Motors Service parts Operation (GMSPO) a preshipment of parts equal to 1 container of hoses (50 pieces) and 1 package of tie straps (50 pieces). Additional parts should be obtained from GMSPO. To ensure that these parts will be obtained as soon as possible, they should be ordered from GMSPO on a C.I.O. order with no special instruction code but order under an advise code (2).

PART NUMBER DESCRIPTION QTY. ----------- ----------- ---- 15960319 Hose, Trans Vent 1 11501906 Strap 1

WARRANTY INFORMATION

Dealers should submit an accurately filled out Warranty Repair Order on each vehicle completed under this campaign.

LABOR DESCRIPTION *TIME ALLOWANCE TROUBLE OPERATION ----------- --------------- CODE --------- ------- V7930 Install Transmission 0.2 Hr. 96 Vent Hose

* For dealer to receive Administrative Time Allowance associated with this campaign, add 0.1 hour to the Labor Operation Time Allowance.

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 may be inserted with a typewriter or ball point pen.

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.

ADMINISTRATIVE PROCEDURE

Procedures covering this campaign are outlined in Section V of your dealership's "GMC Truck Warranty Claims Processing Manual" #P9119.

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.