Hi im new to the forum and couldn't find an answer to the issue im having.

I have a 2013 f150 with the 3.7(non ecoboost)

If I switch to tow/haul mode and go full throttle, the truck will bounce off the rev limiter until you let off the throttle then it will upshift. Truck shifts fine doing the same with t/h mode off

Any input would be appreciated, thanks for spending your time viewing this post

 

<p>Tow/Haul delays the upshifts under acceleration to provide more power. Wide Open Throttle does the same. The combination is causing you to reach the rev limit. Since you have a normally aspirated engine, you don't have a particularly high torque output until you reach high revs. I was able to have the same thing happen between 3rd and 4th gear with my old 5.4L V8. It would not upshift during WOT acceleration until I backed off on the throttle a bit. It seems to me that you are just going to have to learn to &quot;help&quot; it upshift if you are trying to do a max acceleration run by backing off on the throttle as the rpms approach the rev limit. I'm sure you can learn to detect that point by the sound of the engine, I know I could, so you won't even have to glance at the tach.</p><p>It will only take a momentary release of the throttle to complete the shift. As soon as that happens, you should be able to go back to WOT immediately and not have it downshift.</p><p>Your only other choice would be to install a programmer that would allow you to adjust the rev limit higher, but I don't really recommend that. The rev limit is there for a reason, and it's probably to protect the torque converter.</p><p>- Jack</p>

 

Thanks for the information. Just didn't know if I should be concerned or not

 

Are you actually hitting the limiter or just reving pretty high? I ask because a lot of people see the tach get to the high side of 5k and get worried. Redline on the 3.7 is around 7k from what I remember.

Are you running a tuner? Some of the Edge tuners had data flow issues on a quick1-2 upshift and would get stuck and hit the limiter until you lifted a little bit. That might be what's going on here.

 

Its completely stock with no tuner. The limiter is at 7k and basically if you keep it WOT it just bounces off and doesn't shift. I've only been brave enough to keep it bouncing off for second or two but nothing happens until you ease up

 

I'd make it a dealership program then. A stock tune shouldn't do that. My EB will occasionally do it on the 93 tune with the TC disabled from a hard launch. But under those conditions the tires are spinning pretty hard and the onboard nannys are desperately wanting to stop the fun.

 

Thanks for the information. I forgot to mention that this only happens with t/c off. I guess I'll have to give my dealership a call and see whats possible. Thanks again

 

I think the better question is WHY?
Why do you have it in tow/haul mode?
Do you have a trailer attached or are you carrying a ton of weight in the bed???

If not, then the simple solution is to turn off tow/haul mode.

If yes, then WHY are you running at WOT?
Typically anytime I am running such that I need Tow/Haul to be on then I'm not doing a lot of WOT accelerations when the light turns green.

(and if you really do need to be WOT then let it rev up high - that's what its designed to do)

 

wait - think I just got my answer to my previous question.

You have TC off... so you are spinning one tire, right??? (maybe spinning more than one tire depending on if you have a locking diff or 4WD)

THIS is the reason its not downshifting.
Shifting is based on vehicle speed. Your vehicle is not up to speed. You are just spinning a tire. So the transmission lets you stay in that low gear, hoping that you will make the smart choice and back off, regain traction, and then drive away.

 

I don't usually run with tow/haul on I was just trying it out in comparison to tow/haul off from a complete stop to 100km/hr. It possibly could be spinning a tire but I doubt the 3.7 is spinning the tires at 50 km/hr. I could be wrong but many people believe t/h will improve your acceleration simply because it will hold the gear longer and I was just testing that out