F3 V10 gearing down on grades

The tow haul will downshift automatically to a safe lower gear if you hit the brakes. Using the brakes tells it you want additional slowing. Otherwise it will downshift on it's own when the rpm' get too high but by then additional braking may be needed anyway. When we see a steep downgrade coming we slow down with the brakes and engage tow haul just before braking and then it will usually take care of things by itself. On very steep downgrades or if you did not slow down enough at the top of the downgrade additional braking may be needed.

One additional caution about mountain driving is when you have just climbed a pass and expect a long downgrade and will not be using the accelerator pedal, pull over at the top of the pass and put it into park and let the engine idle for a few minutes. Climbing long passes heats the exhaust manifolds up to sometimes cherry red. Going down a long grade at high rpm pumps massive amounts of cool air and little burned fuel to raise the exhaust temp. The result can be a broken cast iron manifold from rapid cooling.

You will often see truck pull over places at the top of passes just to prevent this problem. One other solution is to install stainless steel headers, but that costs $$$.

Coffee Grinder wrote:
Recently was in Colorado and had a couple issues gearing down low enough to be comfortable. Used "Tow Haul" and worked pretty good then tried gearing down to lowest gear on shifter which didn't seem to do as well. Most issue was Wolf Creek Pass . Any advice would be helpful. Thanks

How fast were you going and what rpm?
Transmission will not shift into low gear unless you are going slow enough to avoid over speed on the motor.

It's an automatic, put it in tow/haul and let it do it's thing. It is what it is.

A lot of rigs will be in second on that climb. Not much to go on unless you tell us what year coach and what weight.

We have a Ford but not your year and that transmission. I just gear down going up as needed and use the same gears coming down. If it was your first time being un comfortable would be OK. I have got that way many times but have been going over it since the mid 80s.

Since its multi lanes now you just take your time up and down. Your speed should be where you feel comfortable. I usually use 2/3 going up and 1/2 going down. It is a 6.8% grade and a long way up and down.