ericdwong

I was reading on motorvate.ca tha the owner there had an issue when it came to which manny tranny oil the shop used. He describes having problems with the GL5 style oil and that GL4 style is correct for the maxima manny tranny. I just checked my bottle yesterday of Mobil 1 synthetic 75w90 gear oil I used and it is GL5. I have not had any problems with the GL5 oil Whats the difference between the two anyway?

Daniel B. Martin

Do not use GL-5 in a 4Gen Maxima.

Copied from the Pennzoil site http://www.pennzoil.com/carcare/faq/default.htm#4

2. What happens if API GL-5 gear oil is used in an API GL-4 gear oil application?

API GL-4 and API GL-5 products typically use the same extreme pressure (EP) additive system, with the API GL-5 having about twice the concentration of a API GL-4. In service, these additives become active under extreme load and temperature when the protective oil film can be squeezed away. EP additives work by forming wear-resistant compounds with the metal of the gear tooth surface. As the gears mesh, these compounds shield the gear teeth from direct metal-to-metal contact that would cause wear and damage to the gears. If too little of the active additive is present, proper protection would be compromised. Too much of this additive could cause excessive chemical corrosion of the gear surface. If an API GL-5 gear oil is used in a application where API GL-4 gear oil is called for, chemical corrosion of "yellow metal" components may occur, such as bronze synchronizers, brass bushings, etc. This may lead to shifting difficulties or shortened equipment life.