confused??

[RL06]

Cant figure out the issue on loss of power while pulling 7k lbs. easy day 0-50mph. once i hit 55, it plateaued and wouldnt let me accelerate any faster. wrench light came on and thats when i pulled over to give a look see. Had a minor drip of tranny fluid under the truck. unhooked the boat and good as new. any ideas??

[Rincon07]

Did u ever find out the answer to the problem? I am having the same one.