SYSTEMS
DIFFERENTIAL OIL
CORRECT OPERATION
SAFETY TIPSVARIATIONS
Differential oil is generally known as gear oil or gear lubricant. As such, the SAE has classified it by viscosity; the API has established service ratings. The API service rating of GL indicates the oil is a gear lubricant. A higher service rating number means higher wear protection. Service ratings are as follows:
- GL-1 -- straight mineral oil
- GL-2 -- worm gear oil
- GL-3 -- mild extreme pressure lubricant
- GL-4 -- extreme pressure lubricant for high speed/low torque and low speed/high torque conditions
- GL-5 -- same as GL-4 with high speed/shock load protection
The viscosity of differential oils is typically one of the following: SAE 70W, SAE 75W, SAE 80W, SAE 85W, SAE 90, SAE 140, or SAE 250. Multigrade oils or gear lubricants are possible too.
SAE 80W-90 GL-5 gear lubricant is typical for differential use, but in extremely cold areas 80W GL-5 is more desirable.
SYSTEMS DIFFERENTIAL OIL CORRECT OPERATION SAFETY TIPS