Chevrolet Low Cab Forward 4500 2019 Series Owner's Manual page 290

Recommended Fluids, Lubricants, and Parts
Recommended Fluids and Lubricants
Fluids and lubricants identified below by name, part number, or specification can be obtained from your dealer.
Usage
Automatic Transmission
Battery Terminals
Brake Fluid
Cab-Door Hinges and Latches
Lubricant
Chassis Lubricant
Driveshaft Center Bearing, Wheel
Hub Bearing Lubricant
Driveshaft, Universal Joints and
Sliding Sleeve Lubricant
Engine Coolant
Engine Oil
Power Steerig Fluid
DEXRON-VI Automatic Transmission Fluid.
Petroleum Jelly (outer surfaces)
DOT 3 Hydraulic Brake Fluid (GM Part No. 19353126).
Multi-Purpose Lubricant, Superlube (GM Part No. 12346241) or equivalent
containing zinc oxide.
Chassis Lubricant (GM Part No. 12377985) or high temperature equivalent.
NLGI #2 or #3
NLGI #1 or #2 multi-purpose type grease
50/50 mixture of clean, drinkable water and use only DEX-COOL coolant.
See Engine Coolant 0 198.
Engine oil meeting the dexos1 specification of the proper SAE viscosity
grade. ACDelco dexos1 full synthetic is recommended. See Engine Oil
0 192.
DEXRON-VI Automatic Transmission Fluid.
Service and Maintenance
Fluid/Lubricant
289