Gear oil for trans and rearends

[Hammerhead]

(12-09-2016 )Rawze Wrote:  If you run with high torque,... 75-90 synthetic in tyranny for better life. Highway and dry-van reefer, 80k or less, .. 50w is fine. easier to shift.

rear ends,.. 75-90 or 85-140. It helps keep the backlash down in the bearings and increases tire edge wear life. As well, longer gear train life, and less chance of wheel seals bleeding when it gets warm.

(12-10-2016 )Brock Wrote:  Odd. I was told by Eaton that under no circumstances could you use a 75/90 gear lube or anything of that nature. They say there are galleries that are not wide enough to support the thicker oil and you will run components dry causing premature wear.

I wanted to know because I was considering doing it.

I run above average torque load so I use 75W90 synthetic in my transmission. For any northerner pulling B-trains, I'd recommend it. I have actually found that my tranny runs cooler and quieter with it over 50W
I'd like to run 85W140 in my diff's because of my workload, but being from Canada running OS/OW, I routinely end up parked for up to 16hrs between travel allowances, and at -30C I think it would be too thick and would lead to premature wear from lube starvation getting warmed up...and synthetic oil is too costly to switch grades twice a year with the seasons.