Questions and Answers
GL4 or GL5?
Q. Vince, What is the difference between GL4 and GL5 gear oil? Can I use GL5 when the owner's manual recommends GL4?
Thanks,
TimA. Not being well versed in the chemical properties of the various gear lubes I can only give you a very general answer.
The most common gear lube is 80-W90 weight oil. The GL designations represent characteristics of the oil. Some are designed for smoother shifting, some for a wider range of operating temperatures and others for improved bearing lubrication. GL5 is used mostly in limited slip differentials and can be used in place of GL4, but NOT vice versa.
