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Author Topic: Ford F53 shifting question  (Read 252 times)

Len2

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Ford F53 shifting question
« on: July 15, 2017, 10:58:33 PM »
Hi, I have been monitoring this forum for about the last 4 years while we were deciding on full timing. We have bit the bullet and are now on our first, what we call, big trip. The RV Forum has helped us with many decisions and we appreciate the information we have found along the way. Many thanks.

We have a 35 foot 2013 Itasca Sunstar. It is on a Ford F53 chassis with the V10 engine. I don't know what transmission. I have a question about something I noticed while driving from Austin, Texas to Chama, NM. If I was using cruise control the transmission shifted as I expected it to. However, a couple of times I had to brake going up hill and when I accelerated with the pedal to the floor the transmission didn't shift down. I made it up the hill OK, slowly, but I thought it strange it didn't shift down. I only saw this 2 times so I haven't had a chance to experiment much but the second time I did try to really push on the accelerator to get it to shift and it didn't. My question is, is this something I should be concerned with? a follow-on question is how does the transmission shift? Is it all computer controlled or is there some linkage and/or vacuum assist. I am thinking some linkage is out of adjustment. Thanks for any help or comments.

Len
Len and Nancy
Molly and Rosebud
2013 Itasca Sunstar 35F
2013 Ford CMax

Gary RV_Wizard

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Re: Ford F53 shifting question
« Reply #1 on: July 16, 2017, 10:35:34 AM »
Difficult to say without determining what gear & rpm range it was in at the time. The Ford tranny shifts to maintain rpms in the peak hp-torque range when under max load. If it was already in that range, it doesn't shift just because you push the pedal harder. Basically, if it is already doing the best it can, nothing changes.  Do you recall the tach readings at that time?

Most motorhomes don't accelerate well under the circumstances you described. The move far more weight per horsepower than a car, so acceleration on a steep grade is lacking.
Gary
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Gary Brinck
Summers: Black Mountain, NC
Home: Ocala National Forest, FL

Kevin Means

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Re: Ford F53 shifting question
« Reply #2 on: July 16, 2017, 11:55:21 AM »
Len, I seem to remember that happening with our '99 Allegro, which had a V-10. We climb a lot of grades out here and I noticed the same thing... it sometimes wouldn't down-shift when I tried to accelerate after slowing down while climbing the grade.

I always wrote it off to a less than ideal combination of RPM, vacuum and speed, but I'm no transmission expert. I don't think it's an indication of trouble - the tranny worked well for the nearly 13 years we owned that coach.

Kev
2011 Winnebago Tour 42QD
Towing a Jeep Rubicon Unlimited LJ or an Acura MDX
RVI Brake 2, Minder TM-66 TPMS, 970 watts of solar
(Can't wait to spend more time RVing)
Lakeside, California

Len2

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Re: Ford F53 shifting question
« Reply #3 on: July 16, 2017, 03:50:21 PM »
I don't remember the exact rpms. I think it was around 3000 and 45 mph. The grade was not that steep. I just had to slow down for some reason and when I accelerated nothing much happened. My speed increased slowly, but no downshift. I looked under the engine cover today and imagine my surprise when there was no throttle linkage, just wires. Sorry guys it's been a while since I looked under the hood of a truck. Even more surprise when there was no linkage connected to the accelerator pedal, only wires. I feel like Rip Van Winkle. Anyway, thanks for the responses. I feel better. We have only had the MH since last Thanksgiving. We have been on several short trips and every time we learn something new.

Thanks again,
Len
Len and Nancy
Molly and Rosebud
2013 Itasca Sunstar 35F
2013 Ford CMax

AStravelers

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Re: Ford F53 shifting question
« Reply #4 on: July 17, 2017, 08:58:17 AM »
Your V10 is coupled to the Ford TorqShift 5 speed transmission.

Since your RPM was around 3000 and your speed was around 45mph your transmission had already shifted out of overdrive (5th gear) into 4th gear.  The computer did this.  There is no way to manually select 4th gear, only the computer can do that.  BTW, at the time this was happening, even if you manually sifted from 5th gear into 3rd gear, the computer would not have let the transmission downshift if it detected that doing so would over rev the engine.

The computer most likely knew that if it shifted down into 3rd gear it would have exceeded the RPM limits of the engine. 

If the hill was steeper your speed would have most likely dropped down to around 40mph or slightly lower and the computer would have shifted into 3rd gear.

I have been driving the V10 and the 5 speed, since 2011, in a lot of hilly and mountainous conditions, including our 4 1/2 month trip to Alaska in 2016. 

Several words of caution:
-- First and foremost, most likely, if the hill you were going up, continued for 4 or 5 miles at the same incline, you could be in danger of overheating the transmission and engine.  Especially if the outside temperature was above 90 degrees.
-- I never press the accelerator to the floor.  Not even when I want the transmission to down shift.  Well I guess if I was trying to pass someone I would.
-- Going up a hill I will generally press the accelerator down to 1/2-3/4ths of the way and slowly let the speed drop.  When I sense the engine is starting to load down I will press the accelerator a little harder to get it to down shift and then back off the accelerator a bit to just maintain my speed but not enough to let the transmission shift back up. 
-- Yes, I baby the engine and transmission. I see no reason to abuse the components.  I also plan to not be in such a hurry that I have to rush up the hills and mountains.
--  Listen to your engine and watch your RPM's as you drive in hilly or mountainous conditions.  If you are going up a long hill, a mile or longer, and your RPM's are in the 2800-3000 range, you are in a condition where you should get the transmission to down shift to where your RPM's are in the 3500 to 4000, or even up to 4500 if the road is really steep. 

Bottom line, when going up long hills keep your RPM's up so you don't load down the engine and transmission and overheat the components.

Even with tow/haul mode on, I have not seen a computer which will down shift the transmission soon enough to suit me. 

My biggest gripe about the Ford 5 speed is that it won't let me manually select 4th gear. 
Al & Sharon
2006 Winnebago Sightseer 29R
2009 Chevy Colorado 4X4

http://downtheroadaroundthebend.blogspot.com/

kdbgoat

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Re: Ford F53 shifting question
« Reply #5 on: July 17, 2017, 09:28:28 AM »

-- I never press the accelerator to the floor.  Not even when I want the transmission to down shift.  Well I guess if I was trying to pass someone I would.
-- Going up a hill I will generally press the accelerator down to 1/2-3/4ths of the way and slowly let the speed drop.  When I sense the engine is starting to load down I will press the accelerator a little harder to get it to down shift and then back off the accelerator a bit to just maintain my speed but not enough to let the transmission shift back up. 
-- Yes, I baby the engine and transmission. I see no reason to abuse the components.  I also plan to not be in such a hurry that I have to rush up the hills and mountains.
--  Listen to your engine and watch your RPM's as you drive in hilly or mountainous conditions.  If you are going up a long hill, a mile or longer, and your RPM's are in the 2800-3000 range, you are in a condition where you should get the transmission to down shift to where your RPM's are in the 3500 to 4000, or even up to 4500 if the road is really steep. 

Bottom line, when going up long hills keep your RPM's up so you don't load down the engine and transmission and overheat the components.

Even with tow/haul mode on, I have not seen a computer which will down shift the transmission soon enough to suit me. 

My biggest gripe about the Ford 5 speed is that it won't let me manually select 4th gear. 

My sentiments exactly. I have found that flooring the accelerator pretty much does nothing for me. I do use my cruise control quite a bit, but I am on the gas before the upgrades to keep my rpm's up long before the cruise control would. I wish mine had the 6 speed like the 2016 and up chassis' have. I had that transmission in my F-250 gasser and loved it.
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2016 Leprechaun 319DS

Dragginourbedaround

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Re: Ford F53 shifting question
« Reply #6 on: July 17, 2017, 09:47:12 AM »
I like my V10 and for the most part I'm happy with it's performance. What I didn't like was the shifting while in cruise control. Most of the time it worked well, but sometimes on a little incline it would down shift and jump to almost 5k rpms and scare the heck out of my DW. I finally bought and installed a 5 Star Tune. It changes the shift points. Now when I go up moderately steep hills the engine doesn't jump from 2500 to 5k anymore. It will slowly shift down and rarely goes over 4500. Just drove from FL to CO in cruise control most of the way, occasionally tapping the brake to take it out of cruise control. Like kdbgoat if I see a long hill coming I will be on the gas early.
Gene

2013 Winnebago Adventurer 37F
2011 Honda Fit

Len2

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Re: Ford F53 shifting question
« Reply #7 on: July 17, 2017, 10:04:14 AM »
Thanks for the advice, always welcome. I feel the same way about babying the components. That's why I asked. Now that I know more about how it all works I have a better idea of what to expect. We will be back on the road later in the week. I am not expecting any big mountains, but I should be able to experiment and observe how and when shifting occurs.

I did see the jumps to 5k RPMs and it was a little unnerving. Always learning.
Len
Len and Nancy
Molly and Rosebud
2013 Itasca Sunstar 35F
2013 Ford CMax

 

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