Transmission Oil Question?

Littleurb3

Active Member
Joined
Oct 24, 2007
Location
somewhereville
I have been reading some concerns about GL-5 oils, reading about sulfur eating away the brass syncros components . also came across a owners manual for the AX-15 transmission and its

recommended lubricant for AX 15 transmissions is Mopar 75W-
90, API Grade GL-5 gear lubricant, or equivalent.
Correct lubricant refill or top-off level is to the bot- tom edge of the fill plug hole.

Lubricant capacity is: • 3.10 liters (3.27 qts.) in 4-wheel drive models. • 3.15 liters (3.32 qts.) in 2-wheel drive models. But

everything that i have read about the Gl-5 is a no no can someone explain.
 
Since recommended lube is GL-5, use GL-5 and don't worry about the rest.

This is well stated:

GL5 gear oil is a lubricant with very high extreme pressure performance needed for Hypoid gears where sliding and rolling contacts operate under very high loadings. This is achieved by incorporating high concentration of sulfurized additives. The downside to such high sulfur in oil is it tends to corrode yellow metals, so can ruin parts like brass synchronizers and some bushings. So any equipment needing GL5 performance is designed taking this limitation of the lubricant into account.

GL4 oils are much more friendly to yellow metals, and so are used in equipment where such high load sliding-rolling contacts aren't present. The designers of such equipment aren't as limited in the use of brass parts. So the bottom line is that if your equipment calls for GL4 it probably doesn't need GL5 performance, and you may be asking for trouble down the line if you use a lube it wasn't designed for.
 
Back
Top