Differential oil color.

[cblack13]

I was changing my gear oil for the first time since I’ve owned the truck. Bought at 100k and now has 141k. The fluid was mostly greenish but had a moment of dark fluid come out. What color is “bad” gear oil?

 

[Burla]

green is oem gear fluid, bad fluid would be black or milky.

 

[Octane]

I was changing my gear oil for the first time since I’ve owned the truck. Bought at 100k and now has 141k. The fluid was mostly greenish but had a moment of dark fluid come out. What color is “bad” gear oil?

Sounds like its okay .But it never hurt to change it maybe every 40k.

 

[HEMIMANN]

Gear Oil OCI is a function of duty cycle and age. Age adsorbs moisture through the breather (hint - water isn't a lubricant). Heavy loads consume the GL5 Extreme Pressure Additive Package.

My limit is 4 years or 50k miles.