I know some guys are using synthetic ATF in their DD w/reverse but does anyone know what the Cat brand is? It smells like gear oil , pours light but the viscosity is not listed and the dealer claims he does not know.

No one?

I just went through this last week, smells like 80-90w gear oil, but pours/feels like 15w40 motor oil (at room temps anyway) I baught the $12 bottle from AC but I will not again... I'm thinking synthetic gear lube, something thin next time but I do not see why ATF or hydraulic fluid or just about anything would not work. It's just gears right? pretty primative design overall compared to industrial pumps, motors, drives and such that run in/on all of the above.

Funny how they are tight lipped about the weight of the oil, I know you would need something that flows well cold so as not to inhibit the reverse from engaging or prematurely burn out the motor. I think I may try ATF as soon as I am out of warranty, but until then I feel like I am being held captive. They even go so far as to publish in the manual that using anything but AC drive fluid will cause extensive damage to the DD.

"Only use CAT APV oil or serious engine damage.."..blah..blah..same idea. ATF I'm thinking to.

We have been using ATF for years.

Automatic transmissions have planitary gears so i dont see why you could not use ATF.