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.

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