CAMPAIGN: AUTO. TRANSMISSION FLUID CONTAINMENT

Subject: AUTOMATIC TRANSMISSION FLUID CONTAINMENT (W/RPO MD8 - 2D20; W/RPO M40 - 2D21)

Models: 1988-90 Chevrolet and GMC C/K Trucks with Four (4) Speed Automatic Transmission (RPO MD8) or Three (3) Speed Automatic Transmission (RPO M40)

TO: ALL GENERAL MOTORS DEALERS:

Transport Canada has advised General Motors of Canada Limited that they believe a safety related defect may exist on certain 1988, 1989 and 1990 Chevrolet and GMC C/K Trucks equipped with automatic transmissions. Specifically, Transport Canada is concemed that these vehicles may develop an abnormal pressure build-up in the transmission with the possibility of transmission fluid coming out of the filler tube onto hot engine parts. In addition, it has come to our attention that some owners are operating their vehicles in a manner which results in the pressure build up or are pulling trailers heavier than the vehicle is equipped to pull or otherwise loading vehicles with loads greater than that specified for the vehicle as it is equipped. These conditions can also result in a similar abnormal pressure build-up in the transmission and the possibility of transmission fluid coming out of the filler tube onto hot engine parts.

The possibility of a transmission fluid fire is remote. However, we wanted our owners to have the benefits of the improvements which address these concerns, and the maintenance of a proper transmission fluid level.

These improvements consist of (1) revising the transmission fluid level indicator (dipstick) markings so they can be more easily understood, (2) adding a seal at the fill tube inlet end to help prevent fluid from coming out of the fill tube, and (3) revising the fluid level checking procedure in the owner's manual to provide for a "cold" fluid level check. (Note: A "hot" check must follow when fluid is added during a cold check.)

To help prevent conditions that could cause transmission pressure build-up and the possibility of transmission fluid coming out of the fill tube, General Motors of Canada Limited is providing, to owners, a new dipstick with a lock-seal top and new owner manual instructions and graphics for checking the automatic transmission fluid level.

VEHICLES INVOLVED:

Involved are 1988-90 Chevrolet and GMC CAK trucks equipped with 4L60 (RPO MD8) or 3 (RPO M40) automatic transmissions built within the following VIN breakpoints:

PLANT YEAR MODEL PLANT CODE FROM THROUGH

1988 C/K Truck Pontiac East E SOP EOP 1988 C/K Truck Fort Wayne Z SOP EOP 1988 C/K Truck Oshawa 1 SOP EOP 1989 C/K Truck Pontiac East E SOP EOP 1989 C/K Truck Fort Wayne Z SOP EOP 1989 C/K Truck Oshawa 1 SOP EOP 1990 C/K Truck Pontiac East E SOP EOP 1990 C/K Truck Fort Wayne Z SOP EOP 1990 C/K Truck Oshawa 1 SOP EOP

DEALER CAMPAIGN RESPONSIBILITY:

Since a new dipstick can be easily installed, for the owners convenience, a new dipstick, along with installation instructions and a new owner's manual page insert, will be sent directly to owners of record. Owners may install the dipstick or they may ask a dealer to perform the service at no charge.

CAMPAIGN PROCEDURE:

Refer to Section 4 of the Service Policies and Procedures Manual for the detailed procedure on handling Product Campaigns. Dealers are requested to complete the campaign on all transfers as soon as possible.

OWNER NOTIFICATION:

Owners will be notified of this campaign on their vehicles by General Motors of Canada Limited (see copies of owner letters included with this bulletin). A listIng of owner names and addresses wI11 NOT be furnished to involved dealers.

PARTS INFORMATION:

A new lock-seal fluid level indicator (dipstick), installation instructions and instructions for checking the transmission fluid level will be mailed to owners of record by General Motors of Canada Limited on a no charge basis.

If additional transmission fluid level indicators are required, they should be obtained through regular channels, as follows:

Part Number Description Quantity/Vehicle ----------- ----------- ---------------- 15687192 Indicator, Transniission Fluid Level (RPO MD8) 1 15659781 Indicator, Transmission Fluid Level (RPO M40) 1

PARTS AND LABOUR CLAIM

In the event that the owner request the dealer to install the dipstick, credit for the campaign work performed will be paid upon receipt of a properly completed campaign claim card or DCS transmission in accordance with the following:

Campaign Repair Time No. Code Description Allowance

2D20 2A InstaH Trans. Fluid Level Indicator - MD8 . 3 2D21 3A Install Trans. Fluid Level Indicator - M40 .3

Time allowance includes 0. 1 hour for dealer administrative detail associated with this campaign and also includes parts handling since the dipstick can be installed without bringing the vehicle in a service bay.

SERVICE PROCEDURE:

1. Remove old transmission fluid level indicator (dipstick).

2. Install new lock-seal transmission fluid level indicator (dipstick).

3. Install Campaign Identification Label.

INSTALLATION OF CAMPAIGN IDENTIFICATION LABEL

Clean surface of radiator upper mounting panel and apply a Campaign Identification Label. Make sure the correct campaign number is inserted on the label. This will indicate that the campaign has been completed.

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.