2019 v10 rpm and downhill

[CoreyinWP]

Just drive through some hilly terrain for the first time.

Without tow haul mode on if I had cruise control on and then tapped on the brake the transmission felt like it changed gear and rpm’s would go up to 4500 - 5000 at 40 mph. Almost like it wouldn’t let me coast. Is that a feature or a bug? Newbie with ford chassis Thanks.

[HarryStone]

Sounds like possibly the lock up torque converter unlocking. Normal for brake application.

[Mark Kovalsky]

It is a downshift, not the torque converter unlocking. When coasting, unlocking the torque converter will lower the RPM, not raise the RPM.

With the cruise on the PCM will downshift the trans if the vehicle speed exceeds the set speed. This is to try to keep the speed down to the set point. It's normal.

[HarryStone]

Mark, He said when he taps the brakes...that will disconnect the cruise control.

[twinboat]

Yes, it disconnects the cruise and downshift if you tap the brakes.

I see 4500 to 5000 RPMs on steep downhill runs.

If you want to coast, don't tap the brake to cancel the cruise, hit cancel on the steering wheel.

[CoreyinWP]

Thanks for the feedback. I will experiment further. It was disconcerting seeing and hearing the engine rev so high.

[Jabber Jaw]

Originally Posted by CoreyinWP

Thanks for the feedback. I will experiment further. It was disconcerting seeing and hearing the engine rev so high.

BUT....it's nice when it is doing its job to help slow the coach, when going down a mountain!

One of the great features of the "tow/haul" mode! I drive with mine "On", any time I'm driving the coach! Flat lands or mountains, it does help "slow" the coach. And to me, a fraction of a second could be the difference in avoiding an accident!

A great feature, & the V-10 is built to handle it, too!

[Mark Kovalsky]

Originally Posted by CoreyinWP

It was disconcerting seeing and hearing the engine rev so high.

The computer will not let the engine rev high enough to do any damage.

[US1]

Originally Posted by Mark Kovalsky

The computer will not let the engine rev high enough to do any damage.

I've heard this before but never read how. For discussion; When coasting down a steep grade and the trans has downshifted to aid in slowing down, yet the engine rpm steadily climbs as the grade is too steep, are you stating the computer will upshift the transmission to save the motor, at which point the driver will be more dependent on braking?

[96 Wideglide]

Originally Posted by US1

I've heard this before but never read how. For discussion; When coasting down a steep grade and the trans has downshifted to aid in slowing down, yet the engine rpm steadily climbs as the grade is too steep, are you stating the computer will upshift the transmission to save the motor, at which point the driver will be more dependent on braking?

That's the way an Allison works!

[Mark Kovalsky]

Originally Posted by US1

I've heard this before but never read how. For discussion; When coasting down a steep grade and the trans has downshifted to aid in slowing down, yet the engine rpm steadily climbs as the grade is too steep, are you stating the computer will upshift the transmission to save the motor, at which point the driver will be more dependent on braking?

Yes, that is exactly what will happen. The alternative is to let the engine blow. Then you don't have power brakes or power steering.

[High Road Travelers]

As "Jabber Jaw" noted, I am always in 'tow/haul' mode. If the motorhome is moving, I'm hauling, and most of the time I'm towing also.
It is especially helpful when climbing and descending. Tapping the brake to down shift will save your brakes from burning out and could save your life. The V10 and Allison transmission work well together in mountains. When my rpm's get to 5,000 or so I'm normally going a little faster than I should and tap the brakes to slow back down some.
Thanks,

[twinboat]

Originally Posted by wog099

As "Jabber Jaw" noted, I am always in 'tow/haul' mode. If the motorhome is moving, I'm hauling, and most of the time I'm towing also.

It is especially helpful when climbing and descending. Tapping the brake to down shift will save your brakes from burning out and could save your life. The V10 and Allison transmission work well together in mountains. When my rpm's get to 5,000 or so I'm normally going a little faster than I should and tap the brakes to slow back down some.

Thanks,

Ford V10 and Allison transmission ?

Ford RV chassis use Ford transmissions.

[Mark Kovalsky]

Originally Posted by wog099

The V10 and Allison transmission work well together in mountains.

How did you end up with a GM transmission in your Ford chassis?

GM owns Allison. Ford uses Ford transmissions, and they call them TorqShift transmissions.