Transmission Oil - 80w/90 vs SAE 40/50

[jnbullock]

New member and a new owner of a m932a2. Just drove her back to Tampa from Atlanta without any problems. I read the manuals for the transmission and was surprised that this one had transmission fluid instead of oil. It came with extra cans of train fluid. I changed out the filter and the fluid looks new. Any thoughts on why?

 

[Buffalobwana]

I have definite thoughts. Just my own observations, maybe its just my truck.

I changed my fluids before driving 1600 miles home after buying one in Idaho. I suspect it had tranny fluid, I changed to 15w 40.

I thought something was wrong. Took it back to the guy who did all the work to get it ready. He drained a little, but said it wasn't too much over. It felt like it robbed a lot of power off the line. I was having a hard time getting it moving.

Maybe its just my truck, but I won't use 15-40 again. I have found Oreilley (premium?) tractor hydraulic fluid to work great.