How to Check Lubricant

2500HD with 6.0 L

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 ...
Shifting from Two-Wheel Drive High to Four-Wheel
Drive High
• Shifts between Two-Wheel Drive High and Four-Wheel Drive High can be made at any vehicle speed.
• Shift the transfer case lever in one continuous motion into either the Four-Wheel Drive High or ...





