Special Application Services

○ Severe Commercial Use Vehicles Only: Lubricate chassis components every 5 000 km/ 3,000 mi.
○ Have underbody flushing service performed once a year.

    See also:

    Engine Oil
    For diesel engine vehicles, see “Engine Oil” in the Duramax Diesel Supplement. To ensure proper engine performance and long life, careful attention must be paid to engine oil. Following these si ...

    Customer Assistance for Text Telephone (TTY) Users (U.S. and Canada)
    To assist customers who are deaf, hard of hearing, or speech impaired and who use Text Telephones (TTYs), GMC has TTY equipment available at its Customer Assistance Center. Any TTY user can communicat ...

    Using Cruise Control on Hills
    How well the cruise control will work on hills depends upon the vehicle speed, load, and the steepness of the hills. When going up steep hills, you might have to step on the accelerator pedal to maint ...