I have an 03 2500 auto crew lwb. Question...when pulling my trailer.. 6500# when I start climbing, should I just shift in and out of overdrive, or should I go into second remember its an auto. Truck has 7500 miles. Thanks...Dave

 

I guess it's going to depend on the grade and whether you tranny starts hunting. If it doesn't hunt, you could leave it in OD. If it hunts, take it out of OD.

 

I usually leave it in OD unless the tranny shifts down, then I lock out od until I have crested the grade. That seems to work well running a GCWR of 17000, it also did pretty well running GCWR of 21000.