3.0 power loss

[chaotic4runner]

I own a 92 4x4 with a 3.slow. Recently while on the highway the speed dropped from 70 down to 40 and it would start sputtering. Then the a/t oil temp light comes on. when the truck is cool it runs ok but once it starts heating up the sputtering starts. any ideas? thanks

 

[2Walker5RS]

First I would check the coolant level... Tranny cooler lines go through the rad. Next check fluid level in the tranny.

First 2 things I would look at.