Owner Letter

Dear GMC 1988-90 Sierra Truck Owner:

A product improvement was made on all 1991 Sierra vehicles equipped with automatic transmissions to help in maintaining the proper transmission fluid level. Transmission fluid level is very important to transmission life and performance.

Also, it has come to our attention that some owners 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 result in abnormal pressure build-up in the transmission and the possibility of transmission fluid coming out 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 this concern, 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.)

Because a new dipstick can be easily installed, for your convenience we have included with this letter a new dipstick and an owner's manual insert together with instructions for installing the dipstick. The instructions for the installation of this dipstick are on the reverse side of this letter. However, it you desire, your GMC Truck dealer will install the dipstick for you at no charge.

The enclosed postage paid owner reply card identifies your vehicle. Please complete the card to indicate that the campaign repair has been completed. However, 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 appreciate your cooperation in this matter. We have taken this action in the interest of your continued satisfaction with our product.