8% grade descent

No exhaust brake?

Basic rule of thumb: Use the same gear going down that you used going up. Use the brakes as little as possible.

You should come to a near stop before descending. Then put the transmission in a lower gear. You may even need to be in low.
Rule of thumb in previous post is a good place to start.
Do not use the brakes them selves. You may not have any left at the bottom.

Did you use the brakes firmly to get speed 10 to 20 mph under the limit then coast back up to speed?
Riding the brakes gently to maintain constant speed can lead to overheating.

If you don't have an exhaust brake, check into getting one. It's the best money I ever spent on my truck.

We had a little Isuzu based motorhome, and the exhaust brake would slow us down to walking speed by itself on an 8 percent- just amazing. Our 33' coach now has one - indispensable for big hills, but not like the little one.

Matt B

Yep the tranny should do all the work. Not the brakes. That way if something gives you will have enough brakes to stop your rig. A 8 percent grade with that big of a trailer 2nd sounds good and you might have to be in 1st.

Moved from Forum Technical Support

PatsRock wrote:
Newbie Here. F350 and 37' fifth wheel.

Yesterday I went down an 8 degree slope and left it in Tow Haul while using the breaks on trailer and truck to slow me down. I was thinking I might have been better off starting in 2nd gear at the top of the hill.

What is the correct strategy for braking on a big descent?

Leave the Tow/Haul turned on while towing, works much better than turning it on when starting a descent.

If the Tow/Haul is on it will do the downshifts FOR YOU AUTOMATICALLY, you can however override the Tow/Haul and downshift early by simply adding some brakes. The computer will however only downshift provided you are not going to fast for the next gear down.

The first time I experienced the Ford Tow/Haul automatically downshifting was our 2005 F250 with 5.4.. Kind of a shock when we started going down the grade and the transmission downshifted without any input from me. Once I got used to that feature it really made driving grades much more pleasant no longer wondering when I should downshift..

enblethen wrote:
You should come to a near stop before descending. Then put the transmission in a lower gear. You may even need to be in low.
Rule of thumb in previous post is a good place to start.
Do not use the brakes them selves. You may not have any left at the bottom.

I have been on a lot of highways with 65mph-70mph speeds where "nearly stopping" will result in someone rearending you.. Not sure if you could really apply this to all roads, perhaps a very remote mountain road with no traffic..