System Specifications

Standard Differential
Grade GL5
Viscosity 80W-90

Locking Differential
Grade GL5
Viscosity 80W-90. Do not use friction modifier.

Locking Differential (Diesel)
Grade Use only GM part no. 1052271. Do not add friction modifier.

C3 (HD3500) Dana Axle
Grade Synthetic Lubricant
Viscosity 75W-140