2009 3500 with 80K miles. Owned since new. No mods. Start engine and engage transmission, first or reverse, and occasionally it takes full brake to hold it in place at 700 RPM. Wants to take off to the point of spinning the tires when on gravel. Thanks in advance for your comments/suggestions.

 

i don't know if your truck has a locking converter, but if it does it sounds like the lockup solenoid is going bad

 

Thanks for that John. I will find and let you know.