How to Check Lubricant

2500HD with 6.0 L
2500HD with 6.0 L

All Other Series and Engines
All Other Series and Engines

To get an accurate reading, the vehicle should be on a level surface.

• For all 4.3 L, 4.8 L and 5.3 L 1500 Series applications, the proper level is 1.0mm to 19.0mm (0.04 in to 0.7 in) below the bottom of the fill hole, located on the rear axle. Add only enough fluid to reach the proper level.

• For all 6.0 L and 6.2 L 1500 Series applications, the proper level is from 15mm to 40mm (0.6 in to 1.6 in) below the bottom of the fill plug hole, located on the rear axle. Add only enough fluid to reach the proper level.

• For all 6.0 L 2500HD Series applications, the proper level is from 0mm to 13mm (0 to 0.5 in) below the bottom of the fill plug hole, located on the rear axle.

Add only enough fluid to reach the proper level.

• For all 6.6 L Duramax Diesel 2500HD Series applications and all 3500 Series applications, the proper level is from 17mm to 21mm (0.6 in to 0.8 in) below the bottom of the fill plug hole, located on the rear axle. Add only enough fluid to reach the proper level.

    See also:

    Range Selection Mode (Allison® Transmission or Hydra-Matic® 6-Speed Transmission)
    The vehicle may have a Range Selection Mode. The Range Selection Mode helps control the vehicle's transmission and vehicle speed while driving down hill or towing a trailer by letting you select a d ...

    Oil Pressure
    This display shows the oil pressure in either kilopascals (kPa) or pounds per square inch (psi). ...

    Adjusting the Brightness and Contrast of the Screen
    To adjust the brightness and contrast of the screen, press the MENU button while the rear vision camera image is on the display. Any adjustments made will only affect the rear vision camera screen. ...