mvalbert62

Newbie here. Lately my 2017 XLT 3.5L 4x4 seems to be shifting gears too soon. It seems to shift as soon as the engine hits 1100 rpm and is in 7th gear at 30 mph. This results in a loud and shaky vibration throughout the truck. I find myself having to put the transmission in Sport mode in areas where the speed limit is less than 55 mph to avoid the problem.

Only thing I can add is I had the Cam Phaser Rattle control module reprogram (21B10D) preformed about 2000 miles ago (didn't work - I still have the cold start rattle), but the Ford service department that performed the work assures me that the two issues are not related.

Anyone else have this problem? Thanks in advance.

16IngotFX4

The shift strategy is to shift early. My biggest gripe. I had to fight it in the 6-speed on hilly and curvy roads, it was never in the right gear. It wanted 4th going uphill on a 35mph road with curves slightly slower requiring harsh downshift due to low RPM strategy.

I can't relate to RPM but without sitting in the vehicle myself I have to say your experience is normal.

There may be a TCCM update -you should investigate. Maybe it will alter the shift strategy if it hasn't already been applied.

One thing that intensifies the effect you feel is larger than stock tires. Are your tires over-sized?

RGtx12

The shudder is a known symptom of 21B10. Check 21N08 "PCM Reprogram Due to Engine Shudder". IIRC it can only be performed after 21B10 and essentially flashes the truck back to the as-built data.

YukonCornelius

Your cold start rattle may be your turbo wastegate actuator arms. They certainly rattle on nearly all ecoboosts. Fix is a little spring to hold tension. You can tell it's happening on your turbos by simply placing a finger on the actuator arm, and the rattle will quit. Have to check both turbos. I asked my dealer to look into it and they did my cam phasers!

Here's a photo of the actuator arm, stole it from the fix thread:
https://www.f150forum.com/f118/3-5-w...-fixed-507919/



If this isn't it I sincerely apologize for the diversion.

mvalbert62

Thanks for all the replies. And I bought the same tires that came with the truck about a year ago. So they aren't oversized.

Bluegrass

Just for clarity.
Is your truck a 150 or 250?
Looking at your statistics causes the question.
.
I live just off a steep hill still climbing.
As my truck slows going around a 90* turn, going uphill, my drive is right there.
I can feel my trans down shift through the gears adjusting to the speed as I lift the throttle for the left turn-in.
My truck is an 18 5L so not the same as yours.
As I understand it, the programs are not supposed to allow the engine to lug by not downshifting at an appropriate speeds and throttle applications.
The down shifts feel like the engine is lightly missing but can't be any different when so many speeds are present to drop through. If it went from one to another skipping gears the change would be even more noticeable than it is.

Gator9329

My truck ( 2015 Lariet with 3.5 echo /6 spd /bigger tires than stock) lugs around 1k to 1300 RPM. When I'm getting on the highway from the onramp it chugs and lugs. I wish it would stay in a lower gear without me having to get deeper into the pedal to get it to down-shift. I feel like the trucks sole purpose is to get into the highest gear as soon as it can.
I spend so much time hovering around in that 1000 to 1500 RPM zone.
I'm not sure if a tune would help or maybe a modified transmission fluid would be the answer.

Bluegrass

GATOR, Did you not understand that larger diameter tires and higher weight would drop the engine RPM and lug the engine more?
It has changed the overall gear ratios in every gear, that >lowers< the engine RPM per gear.
You would have to change the rear axle ratio to compensate for the change just to run larger tires.
If you have 4wd, the front ratio has to be changed to the same as the rear.
No program change can account of what mechanical drive line changes has been made except the RPM and road speed up-shifts and down shifts occur.
The power to do this still comes from the engine.
The only >>small<< advantage you get is the engine makes a bit more power at higher RPM to each up-shift point.
When the axle gear ratios are lowered to make up for the larger tires, you get both higher engine RPM and gear ratio torque multiplication.
Both together make the biggest difference you're looking for.
Then performance programming added, become a bonus.
And the costs of running the bigger tires begins to add up.
There is a decision to be made for worth of all the investment.
Good luck.

YukonCornelius

We have plenty of gears in this 10 speed to go around. Probably too many. Bluegrass everything you say is true, but at the same time, we would get less gripes if the shift points were better, or the darn adaptive leaning programming junk would just disappear. 2nd gear should not be skipped unless you're going downhill or something! Whether people use bigger tires or not, the final drive ratio can only really cause problems in 1st gear. With this many gears, there's no reason this transmission cannot stay in a practical place in the power band, but it CHOOSES not to. That's the problem and only a transmission tune can fix it because Big Ford does not care about our crummy two year old vehicles.

mvalbert62

Hi Bluegrass - 2017 F150 3.5L