Originally Posted by WearyTraveler
Wouldn’t this red line my engine?
The red line on the Triton V-10 is 5,200 rpm (two and three valve engines). The engine ECU (engine control unit) will always limit the engine to this maximum, on or off throttle. Even if you manually shift into second gear on a steep downgrade and the coach and toad gradually increase speed to 5,200 rpm, the transmission will up-shift 3rd gear. As soon as you decelerate down to about 3,600 rpm the transmission will downshift back into 2nd.
If I am approachable a decent over 6%, I always shift into 2nd and modulate the throttle to maintain about 35 mph (4.30:1 rear axle with 33" dia tires) using the engine and brakes to show down of the 15 mph curves. Always better to go show and be able to avoid a deer or errant car than to keep up with traffic. Of course I have a light weight coach and toad (21,50 lbs total). Slumguillion Pass on CO-149 will teach you how to manage the throttle, gear shift lever and the brakes.
As stated before, T/H mode does several things: increases the internal transmission pressure to allow faster, surer shifts; holds the transmission longer in a lower gear before allowing up-shifts; increases the average up-shift points by about 15%; and revises the downshift protocol.