The vehicle is a 2006 F150 SuperCrew FX4 5.4L
I bought it on Monday, and have been noticing a small shifting issue.
Under light-moderate acceleration, the transmission will run through first, shift to second, then to third, and about when it feels like it should go to fourth, it sort of jolts or hiccups (very little RPM change), but it is fairly harsh (like someone tapped your bumper), then it feels like it locks the torque converter, THEN shifts up to forth gear.
It was hardly noticeable at first, but when I installed a program from my x calibrator 2 with firmer shifts it was VERY harsh. I returned the computer to stock and had my tuner try to smooth the shifts a bit. It was a bit better, but still there.
Now, if I lockout O/D, and accelerate all the way up to fourth gear it is perfectly smooth. I can then let it go into overdrive from fourth gear, and it is smooth.
Same story if I accelerate hard all the way through, 1st, 2nd, 3rd, 4th, then it locks the torque converter.
The problem is only under light-moderate acceleration, like normal starting from a traffic light. I don't believe it is an actual tranny problem since locking out overdrive fixes it, I think it is something with the programming. Again, it does this with stock software.
My tuner guy has no idea why it is doing this. I tried to datalog with the xcal tuner but I was unsuccessful.

What do you guys think? Could it be trying to shift and lock the T/C at the same time? The truck is not under warranty so I really don't feel like having to pay the dealer to plug their computer in to see what it's doing. I'm going to keep working on data-logging but any advice would be a huge help!
Thanks
Brian

 

Alright, first thing is that the RPM change in between 3rd and 4th under light acceleration is the torque converter locking. Reason it's being harsh is well... you already said you changed settings with your XCal2. There's your cause most likely.

Also @ the bolded, when overdrive is locked out you can't get into 4th...
We don't have 5 gears. 4th gear IS overdrive.




With my performance tune from VMP, the torque convert doesn't lock if you're giving it gas at all unless it's above 50, stock the TC would lock under light acceleration in between 3rd and 4th.

 

Thanks for the input..
But the problem still persists when everything is turned back to stock. Not nearly as bad, but it is still there.
Here's the other thing. My understanding is that the torque converter will not lock up with the brake switch engaged, right? I've tried a few runs with the brakes lightly touched (enough to keep the brake lights on), and it still does this.
As a last resort, my tuner is going to return most of the shifting stuff to stock. The second tune he sent me was barely firmer than stock and still much more noticeable.
So let me think here...
With O/D off (works smoothly), it still has the apparent shift into "fourth", so the last "shift" must be the torque converter locking smoothly in third. So the issue should not be the torque converter locking up in third, right?
With O/D on, this rough "shift" happens after the apparent third gear. Maybe it is shifting into O/D and locking the torque converter at the same time? I don't know, it's strange.

How much has your in town mileage dropped by not allowing the torque converter to lock below 50mph without gas? Because I suggested to program it to not allow locking below 40mph or something along those lines and he said it would kill my mileage..? Did you suggest this setup or did the tuner do this by their recommendation?

I wish these trucks were available in manual transmissions with the 5.4. This is the second auto I've had (other was an 05 sport trac) and I can't stand it. The only "good" auto I've driven is the Torque-shift autos with a PSD.

 

Drive faster than 50.

Stock the TC won't lock below 40 most the time anyways, so I don't know what your friend there is smokin. The reason it stays unlocked is for increased throttle response, now when I put my foot down a little I get instant gratification.

 

I suppose I should also mention that he tuned my Sport Trac for me and it worked great. Shifting was much improved over stock. Something is just a little off with this and I can't make sense of it. I really wish I had a good way to tell what exactly the transmission is doing. If the damn thing would datalog like it should with livewire I could probably figure it out.

 

If only you were in Danville Indiana instead of Danvile Kentucky I would definitely try to help you straighten it out in person. Tough to do over the internet though. People describe things differently and often it isn't what it sounds like to the reader unfortunately.

If you have the brake set enough to turn on the brake lights then it likely isn't the converter locking.

Darrin

 

Yeah, auto transmission deals are hard for me to explain, when I don't fully know what it is doing. I don't know if it is a bad 3/4 shift under light throttle or what. If you were a little closer I would take you up on your offer.

It's frustrating for sure though. Does anyone think the dealer would be able to properly diagnose this by hooking up their computer and going for a ride? I get the feeling they would either say "that's normal" or "we're going to have to rebuild the whole thing", lol. Just my experience with dealerships anyway. Either don't want to touch it want to empty the credit cards just for fun.

 

i think mine kinda does this.. gently accelerating from a stop.. at just about 30mph sometimes it will "flair shift" it seems as if it goes 1 2 3 2 4 at least that what it feels like cause the truck bumps the rpms go up and then it bogs into overdrive. i do have 35's but i ciant imagine that they woulda messed up the stock computer calibration that much..

anyway i dunno if this is the same problem your having or not but i have noticed somethign funny in the trans around overdrive.. and mine has 4k miles on it

 

The wierd shift you are feeling is from 3rd (D) to 4th (od). What is happening is the transmission shifts into 3rd (D) then the TC locks then before the transmission shifts into 4th (OD) the TC is unlocked causing the RPM to jump, then the transmission shifts into OD and locks the TC again. The 3-4 shift is a solenoid as well as the TC lock, both are controlled by the PCM and under light throttle acceleration the PCM wants to lock the TC as soon as possible for better fuel mileage so as soon as the the the 3-4 shift solenoid is energized the TC locks which is felt as a bump. The only way around the situation is to either accelerate a bit faster or retune the pcm shift points.

 

Thanks LastSplash, that is exactly what I decided it was doing after driving more today. It feels like it unlocks the torque converter and shifts into O/D at the same time.
Whatever was done with the Xcal tune just made it worse at first like it was going to drop the tranny. So the shifting changes were backed off and it is only as bad as stock now, lol. I've started to lockout O/D in town a bit more, or if I'm lightly accelerating in traffic.
I suppose the proper way to get rid of this with tuning would be to not allow the TC to lock up below certain speeds like Acra_ex did. But it does seem like it could kill economy at slower speeds around town.
I'm a bit disappointed that the guy tuning it couldn't improve it, but oh well. He did work on it a lot though and did what he could while having to try to understand what it is doing based on what I told him...

 

Mine does the same thing. Just bought my '05 screw 5.4
4x4. It has the hard jerk when I barely touch the throttle.

So does this mean that a solenoid is going bad or is this normal?

 

My new '08 did the same sort of thing at 7K miles. My biggest concern was the flare when shifting to third. Took it to the dealer and they had a bulletin describing this sort of thing and installed a new shifting progran. This fixed the flare and reduced the feel of the torque converter locking up.

 

Thanks for the reply. It's not very noticeable any more, for whatever reason. I'm waiting on an intake and catback, then I'm going to have some else write a new tune for the xcal 2 and see what it does.

 

hey there i just got mine fixed at the dealer. they re flashed the tcm and it took care of it! at first they told me to go away and there wasn't any problems but then then i talked to the shop foreman and he updated it.. it not only took care of the flair shift, but the trans seems to shift better as well!

funny cause my engine made a ticking sound which they also said didn't exist... and now my truck has new cylinder heads and the noise that didn't exist is gone... very strange, very strange...


JOSH

 

I figured I should update this thread.
Since installing tunes from VMP tunes the shifting issue is completely gone. It shifts perfect now!
I don't know what the previous tuner did, but it was a mess!