2015 F350 hard downshifting (6th to 5th)

Power-Stroke

Active Member
Anyone having an issue with hard downshifting from 6th to 5th with their F350?

Truck:
2015 F350 DRW (11,500 miles)
6.7 diesel
tow/haul mode
airbags
stock (no tunes or mods other than airbags)

Scenario:
Towing (Cyclone 4200) through the mountains and experienced very hard downshifts (under acceleration) when climbing grades. I don't experience when downshifting going down a grade. Maybe normal..... maybe not!

Appreciate any thoughts or insights.

Jay
 
Last edited:

Bighurt

Well-known member
Are you tuned or stock.

Tow-Haul Mod or just normal?

When hauling up a long hill and trying to accelerate the truck in tow haul will down shift to keep in the RPM band while accelerating. Downshift to get moving than upshifts to lower the RPM. When you are going 60 MPH and it does it with a load it's pretty pronounced. Scared the crap out of me first time mine did it passing a Prius hauling 14.7K up I-10 bound for Albuquerque NM. Scared them too, cause I'm tuned with nothing turbo back...Rolled coal accelerating past them to 70mph, I was behind scheduled.
 

jassson007

Founding Louisiana Chapter Leaders-Retired
No issue like that with my '14 but I also have not towed in the mountains.


Sent from my iPhone using Tapatalk
 

Bighurt

Well-known member
Updated original post with additonal info. I was in tow/haul. Truck completely stock.

Thanks,
Jay

My answer stands having a tuned truck would not have necessarily changed the scenario. Although towing in a race mode would not be good for the tranny.
 

jeffdee

Well-known member
I have a 2015 F350 Lariat with 5000 miles at 6 months old. Experienced no transmission issues in tow/haul or normal driving modes.

I have pulled my 3110 TH a total of 1500 miles with this truck. It has 4.30 gears and averages 10.5 to 11.5 mpg towing.
 

chaplady

Well-known member
I had a 2011 that had to have 2 shift modules replaced due to it not upshifting smoothly. I believe it was 2nd head and 6th gear.
 

jam20ster

Well-known member
I have noticed the few times I have hauled my 4200 up decent grades that it will drop the 5th relatively smooth, but then drop into 4th and this has a bit of noticeable feel. Nothing though that I believe to be out of the ordinary though.

As far as the downshift on decent goes do you have the exhaust brake on? The exhaust brake should be used at all times when hauling. This helps with deceleration and saves brakes on both truck and trailer, especially in the hills and mountains.
 

Wmnmy

Well-known member
I have a 2015 f-350 king ranch with 9000 miles been from west to east coast and back with no problems with shifting ....
 

Power-Stroke

Active Member
Appreciate all of the feedback. I do have the exhaust brake engaged.
The hard downshift may be normal given the weight being pull and the grade (6%) I'm accelerating up. The transmission temp is stable (200 +/-) and nothing else is out of norm (no noises, etc.).... just a very pronounced (hard) downshift. I don't have any relativity for what's normal. I'm headed to Navarre, Florida in a couple of weeks.... I'll see how it's does on flat roads. Absolutely love the truck! Pulls like a freight train and is very comfortable for my family when clicking off miles!
Thanks,
Jay
 

jam20ster

Well-known member
Agree these trucks are strong. Very impressed with its ability to haul 18+K all day long. Also on the 2015 F350 not only do you have 0-10 gain on brake controller, but under settings you can adjust the trailer brake sensitivity from low/mid/high. I have mine set on 10 and high and seems to do really well.

Other years models may have the same along with F250's, but not sure.
 

pegmikef

Well-known member
I have 26K miles on my 2013 F350 of which between 17 and 18K are towing miles and have never experienced what the OP has described. I pull in tow/haul and I always leave the gear listing displayed so I can watch it shift up or down. The steepest grade of any length I know of that I have been over is the seven percenter on I-10 north of San Antonio.
 

porthole

Retired
Anyone having an issue with hard downshifting from 6th to 5th with their F350?

Truck:
2015 F350 DRW (11,500 miles)
6.7 diesel
tow/haul mode
airbags
stock (no tunes or mods other than airbags)

Scenario:
Towing (Cyclone 4200) through the mountains and experienced very hard downshifts (under acceleration) when climbing grades. I don't experience when downshifting going down a grade. Maybe normal..... maybe not!

Appreciate any thoughts or insights.

Jay

The engine, transmission power train control modules "learn" how you drive and adjust the programming as the system see fit based on the factory parameters.
It is very possible the coding got buggered, especially if this is something new.
A simple fix may be nothing more then having the PCM'S flashed, resetting your baselines.

Harsher shifts can be expected when hauling heavy, and in T/H mode, especially uphill. The converter is locked up earlier and in lower gears, shift points are higher as well as increased line pressures.
Do you notice more ofter with or without cruise control engaged?

Keep in mind, when torque converters "lockup" it is similar to having a clutch fully engaged, there is no "give" in the torque converter when locked.
 

Power-Stroke

Active Member
@porthole - i don't recall if it happens while the cruise is on (great question). I have a scheduled trip to the RV dealership tomorrow and will see if it happens with cruise. Afterwards, I'm going to have the Ford dealership take a look and possible reflash.

Appreciate everyone's time.

Thanks,
Jay
 

Geodude

Well-known member
My 2011 exhibited hard shifts in all driving and towing conditions for the first 2-3 years, notably going into 3rd. The dealer reset it a couple of times so it could re-learn, and later on played with the programming. The last go at it seems to fix it. Lately I've found it's doing a hard shift 3 to 4 and 4 to 5 again, when towing, and in tow/haul mode. Our Bighorn isn't a whole lot heavier than our Greystone was (maybe 1,000 pounds). I'm going to have to pay more attention to the terrain and other conditions to learn more precisely when it does it. Then maybe get the dealer to look at it again.
 

Power-Stroke

Active Member
Well.....

I towed the 4200 to the dealership today on relatively flat ground and did not experience any hard downshifts (both on/off cruise). Afterwards, I drove home (w/out the 4200) and each and every shift (up/down) was smooth as butta'! I still decided to stop by the dealer just for a second set of eyes. After checking line pressure, etc...... nothing wrong! Guess it's all normal. The pcm was reset.

Really appreciate everyone taking the time to share their thoughts and insights.

Jay


Sent from my iPad using Tapatalk
 
Top