Differential oil

[JRS]

According to my DVD, looks like the front/rear axles of the 2500/3500 use a synthetic 75W-90. I find it odd that the line above that states the 1500 rear axle uses a synthetic 75W-140. I would have thought the HD trucks would use the thicker oil.

 

[Wingate]

The 1/2 tons did NOT use the AAM axle at one time. Seems as though theyused the Dana axle... . different manufacturers spec'ed for different oil.

THat being said, I run 75W140 Valvoline synthetic in my CTD... . The AAM axle was running hotter than I reallly wanted when towing during summer months...

 

[BurlesonR]

Yeah, I also run 75w140 synthetic to keep things cooler.

 

[HBarlow]

I use either or a mix of each weight depending on what my local Autozone has. Always the same brand and always synthetic but either viscosity seems to work as well as the other.