New to me '03 Dmax k3500. I haul a Lance 835 camper (approx 2300 lbs loaded with our gear). I will also occasionally tow a 16' smokercraft osprey. Tow/Haul necessary or not? vs OD off?
Just not sure what's necessary since I don't tow a 10k lb 5ver or anything that heavy. No pyro installed (yet).
Owners manual not much help. I read it, but it didn't stick as to when to use vs when not to use.
Thanks

Take a look at the sticky post up top, lotsa cool info for someone thats new to the allison trans.

OD lock out keeps your truck from going into OD or 5th gear. No reason to use it unless you find your truck is "hunting" between 4 and 5. TH provides more agressive grade breaking witch you may or may not like, need but it locks the converter sooner so durring in town type stuff it will keep your trans cooler. It will rasie shiftpoints and the trans wont have its caddy like feel but I would run it in town if you can stand it since it will keep the trans a wee bit cooler. Once on the highway at a cruise though it dosnt make and difference if its on or off.