Only driven the tractor around the yard (big yard). Transfer case does have an issue and will not stay in high unless you hold it, so most driving is in low. Of course there is a huge difference in weight, the tractor is maybe 14-15,000# bare with everything I have taken off and the water truck must weigh at least 26,000# empty. Also, the big truck has 1400x20 tires and the tractor only 1100x20's. Once I cleaned out the mice, the Mack runs great, and is very responsive, much more so that the Cummins in the M812. The water truck is not bad, but it still acts like a great big gas motor and at lower rpm is not as quick as a diesel. But, being able to rev to 2,800-3,000 rpm does help on the road through the gears.
A pdf of the TM would be great if it can be done. Thanks