Chevrolet Low Cab Forward 4500 2019 Series Owner's Manual page 291

290 Service and Maintenance
Usage
Rear Axle
Rear Axle
(Limited slip differential (LSD))
Windshield Washer Solvent
Be sure to use the LSD gear oil
additive mentioned above in
vehicles equipped with limited slip
differentials, and ensure there is an
appropriate amount of the LSD gear
oil additive, otherwise a chattering
noise and/or excessive vibration
may occur when turning.
If abnormal noises occur despite
having used the specified LSD gear
oil additive, have it inspected and
serviced at your dealer.
Multi purpose gear oil SAE80W-90 GL-5, SAE90 GL-5
Multi purpose gear oil SAE80W-90 GL-5, SAE90 GL-5 for limited slip
differential together with limited slip differential lubricant additive (GM
Part No. 88900330) or equivalent.
Automotive windshield washer fluid that meets regional freeze protection
requirements.
Maintenance
Replacement Parts
Replacement Parts
Please contact your dealer for
genuine GM parts.
Warning
If part replacement is necessary,
the part must be replaced with
one of the same part number or
with an equivalent part. Use of a
replacement part of lesser quality
may result in personal injury or
damage to the vehicle.
Fluid/Lubricant