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Old 02-24-2017, 07:39 PM   #1
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Downshift on downhill braking

We just got back from north Arkansas and some hilly country and had much more downshift while braking downhill than we've experienced before. While going slowly downhill, 45mph maybe, if I touched the brakes for a tight corner, it would downshift and often started taching 4500 rpm. On prior trips it would downshift but it tended to stay in the 3000 to 3500 rpm range.

It seemed to act identically with the tow-haul button pushed or not; I couldn't tell any difference. And I couldn't make it upshift. Often we'd level out, and the engine would still be screaming as I ran along on level ground. I found that I could accelerate, and it'd upshift, but I'd have to get it revving near 5000 before it would. And I wasn't wild about accelerating on downhill curves.

Oddly, after we out of the slow hills, I discovered I could make it upshift by pushing the tow-haul button to turn it on then push it again to turn if off. When I turned if off it'd upshift. But I discovered that too late to experiment while it was trying to float the valves out of the head (OK, I exaggerated there, but I don't like the R's that high.)

I understand the purpose and am glad it downshifts to aid in saving the brakes. My wife uses this rig by herself or with her 80-year-old mom, so I appreciate the added safety factor. But is it normal to wind that high?
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Old 02-25-2017, 12:10 AM   #2
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If you don't think it is right then take it to FORD to get it checked out.
But from what you have said it appears to acting correctly. TOW/HAUL is actually Hill Descent Mode and is a good thing to have. Read the included FORD Chassis manual. It has some good info in it about how the transmission is supposed to perform.
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Old 02-25-2017, 03:12 AM   #3
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EdinArk, your post is a perfect description of my experience. I didn't think anything is wrong per se, although I had the same question about the difference between that and tow haul as well. Someone suggested using tow haul whenever we're towing even in town and I have appreciated the extra control without using brakes a much. I consider the transmission "braking" (tow haul on or not) kind of like cruise control - it doesn't know what I'm seeing ahead so it doesn't always do what I want when I want. I use the method you describe if I'm not comfortable accelerating - turning tow haul on and off - to get it to release.

Not much help but confirming we've had the same experience.
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Old 02-25-2017, 04:47 AM   #4
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EdinArk, your post is a perfect description of my experience. I didn't think anything is wrong per se, although I had the same question about the difference between that and tow haul as well. Someone suggested using tow haul whenever we're towing even in town and I have appreciated the extra control without using brakes a much. I consider the transmission "braking" (tow haul on or not) kind of like cruise control - it doesn't know what I'm seeing ahead so it doesn't always do what I want when I want. I use the method you describe if I'm not comfortable accelerating - turning tow haul on and off - to get it to release.

Not much help but confirming we've had the same experience.
Confirming that we are having the same experience is helpful. Thank you.

Our old Class C, also with the V10, acted notably different with the Tow/Haul switch pushed. This one seems to think it's pushed all the time.
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Old 02-25-2017, 05:01 AM   #5
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If you don't think it is right then take it to FORD to get it checked out.
But from what you have said it appears to acting correctly. TOW/HAUL is actually Hill Descent Mode and is a good thing to have. Read the included FORD Chassis manual. It has some good info in it about how the transmission is supposed to perform.
Yeah, I know FORD is the place to take it if I think it's not right, but I'm trying to determine if my experience is similar to others. I didn't get a manual, but I managed to find one to download. It does describe the Tow / Haul button and what it does. It does not, however, tell me what RPM ranges to expect.

We have now put about 2500 miles on it, and this is the first trip it's spun the engine up to 4500 going downhill. But thinking back on previous trips, the roads we were on were slower and hillier than any we've been on before.
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Old 02-25-2017, 05:20 AM   #6
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Our 2016 is very aggressive downshifting on hills. It winds up to 4500 rpms routinely no matter whether tow-haul is on or off. I have been told by other people that their rig does the same thing, but I sure don't like listening to it rev like that.
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Old 02-25-2017, 07:35 AM   #7
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Doesn't sound right to me

My 2016 6 speed did not work properly from new delivery. I was involved in getting Ford to recognize there was a problem. I was one of the first to receive the new program to correct the tow/haul for certain 2016 models. In my case, before, tow/haul didn't work at all. Now it does. There is a significant difference in deceleration with and without tow/haul engaged. With tow/haul off, there is no aggressive downshifting at all. It does downshift, of course, but not as an assist to deceleration. Only in preparation of acceleration and being in the proper gear.

In my opinion, if there is no perceptible difference with the tow/haul on or off, that is not right. With it off, there should be no aggressive downshift that would high RPM the engine when the brake pedal is depressed.
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Old 02-25-2017, 07:51 AM   #8
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My 2016 6 speed did not work properly from new delivery. I was involved in getting Ford to recognize there was a problem. I was one of the first to receive the new program to correct the tow/haul for certain 2016 models. In my case, before, tow/haul didn't work at all. Now it does. There is a significant difference in deceleration with and without tow/haul engaged. With tow/haul off, there is no aggressive downshifting at all. It does downshift, of course, but not as an assist to deceleration. Only in preparation of acceleration and being in the proper gear.

In my opinion, if there is no perceptible difference with the tow/haul on or off, that is not right. With it off, there should be no aggressive downshift that would high RPM the engine when the brake pedal is depressed.
Thank you so much. I'll contact a dealer.
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Old 02-25-2017, 08:55 AM   #9
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Computer set maximum rpm for the Ford V-10 is 5,250 pm. The engine computer will NOT let the engine exceeded that rpm. You should not be concerned if the computer chooses to operate the engine the 4,000 to 5,100 rpm range as it is trying to protect the brakes. In tow haul mode, the computer will show a preference for engine braking over hydraulic brakes and it will hold the engine in a lower gear longer in anticipation of a need for more power or more engine braking.
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Old 02-25-2017, 09:00 AM   #10
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Computer set maximum rpm for the Ford V-10 is 5,250 pm. The engine computer will NOT let the engine exceeded that rpm. You should not be concerned if the computer chooses to operate the engine the 4,000 to 5,100 rpm range as it is trying to protect the brakes. In tow haul mode, the computer will show a preference for engine braking over hydraulic brakes and it will hold the engine in a lower gear longer in anticipation of a need for more power or more engine braking.
Good information on the rpm range. Thanks.

To be clear, though, the RV was NOT in tow / haul mode at the time. And it can be upshifted by switching to tow / haul then back. Doesn't seem right, but I wondered if that was usual.

Our E450 did that in tow / haul mode, but not out of it. There was a very clear difference driving that in with tow / haul off or on. Not so the F53.
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Old 02-25-2017, 09:28 AM   #11
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Hello Ed,
mine also does down shift going down hill even if Towhaul is off. Noticed it in Colorado last summer. Expect to be in North Arkansas later in March. Remembered a pretty good hill going into Leslie and another one going into Marshall. I will see how it does there.

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Old 02-25-2017, 09:39 AM   #12
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We know the computer programing is different between the 5R110 and the 6R140 mainly because of the change in engine power parameters. Since our coaches are similar (on the same chassis), I would suspect what you and I experience is also similar. We had the coach in Colorado in September and traveled over several passes above 11,000 ft (Slumgullion, Monarch). I came down the passes in second gear at 4,500 - 5,000 rpm and still had to use the brakes a lot and I wasn't towing. The computer had the coach at 3,200 to 3,800 rpm in third gear climbing the same passes. I find the computer is more aggressive with the cruise control activated in down-shifting and delayed up-shifting.
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Old 02-25-2017, 10:35 AM   #13
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Hello Ed,
mine also does down shift going down hill even if Towhaul is off. Noticed it in Colorado last summer. Expect to be in North Arkansas later in March. Remembered a pretty good hill going into Leslie and another one going into Marshall. I will see how it does there.

Rick
You're spot on. The long hills you've mentioned on Hwy 65 were the most annoying.
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Old 02-25-2017, 08:58 PM   #14
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Don't confuse with cruise control downshifting

When analyzing the tow/haul, no tow/haul don't confuse the issues with cruise control. All by itself, cruise control will command a downshift if going downhill and the speed increases by a set amount. Some have stated that set amount is between 7 and 12 mph gain for a cruise control initiated downshift.

A brake pedal depression with tow/haul on will initiate a downshift.

A brake depression with tow/haul off does not initiate a downshift.

A speed increase of 7 to 12 mph with cruise control on will initiate a downshift
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