How to Check Lubricant
To get an accurate reading, the vehicle should be on a level surface.

1500 Series
A. Fill Plug
B. Drain Plug

All Except 1500 Series
A. Fill Plug
B. Drain Plug
• When the differential is cold, add enough lubricant to raise the level from 0mm (0 in) to 3.2mm (1/8 in) below the fill plug hole.
• When the differential is at operating temperature (warm), add enough lubricant to raise the level to the bottom of the fill plug hole.
See also:
Owner Checks and Services
At Each Fuel Stop
• Check the engine oil level. See Engine Oil on page 10‑7.
Once a Month
• Check the tire inflation pressures. See Tire Pressure on page 10‑62.
• Inspect the tir ...
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 ...
Leaving After Parking on a Hill
1. Apply and hold the brake pedal.
2. Start the engine.
3. Shift into a gear.
4. Release the parking brake.
5. Let up on the brake pedal.
6. Drive slowly until the trailer is clear of the chocks. ...





