Manually shifting your auto

there is jake brakes in the engine, we combine that with compression braking which is downshifting to bring up the rpm's. I dont drive too many dump trucks at work anymore, still have the c.d.l. though.

 

I downshift my auto transmission when going downhill. I've been doing it with many different vehicles of the years. A doubt that a downshift into 3rd is going to hurt your transmission. It will haul 5000lbs after all

Cheers.

 

Yea EricT (thread starter) says he puts it in third and notices it will downshift but not upshift, thats what its for, the ability to select,... just dont race it to redline, why misuse it.(dont think he was doing that though)
also the part about holding it in a gear then upshifting, like above... if you are towing and you arent going to the redline, holding it gear longer just raises rpm at cost to fuel efficiency. The next shift up will land you at a higher rpm so you can maintain speed on a grade.
Once again i dont know your redline on the v6 so if its 5000, you would never really need to go to 4000 rpm, if you did i doubt it would do any harm , just consider the grade length, grade%, and how much you actually are towing.