Hello F-150 experts,

My brother and I just finished up a 1,200 mile drive with his 2004 Heritage F-150 4.6L and one problem we noticed was a high-rev issue when shifting out of overdrive.
He’s experienced it a few times but this long two day drive exaggerated it plus we had almost 1,000 lbs of added weight.
I-70 through parts of Kansas has decent enough grades that required at least 3,000 RPM in 4th running at 75-78 MPH with cruse on.

When the transmission shifts out of overdrive, it would high-rev to 4,000 RPM or a bit higher then drop to 3,000 or whatever RPM’s it needed to pull the grade.
Sometimes something would briefly squeak at the end of the high-rev/just prior to the RPM’s dropping as 4th takes over again without O/D.
Same experience without cruse and accelerating hard with the pedal, such as needing to get out of the way of a semi operator.

Drive without O/D (tow/haul mode) and the shifts are great and the transmission is very responsive even downshifting to 3rd but obviously it’s running at higher RPM’s all of the time.
If we could, we would turn off O/D before the hill to help prevent the issue when O/D couldn’t pull the hill.

The faster the speed the more dramatic the rev when things are heated up.
Surprisingly though, shifts are smooth when this happens.
It doesn’t slam into gear even with those high RPM’s, for example.
I have had plenty of experience with high revving, hard shifts with my 2011 F-250 (malfunctioning shift solenoids).

I would have said it’s normal but the brief squeak concerns me.
Some component is being stressed I just don’t know what that would be.
Clutch or torque converter issue?

Extended cab 4x4
4.6L V8
Auto 4 speed with o/d (I’m guessing the 4R70W)
Transmission fluid is full, smells fine.
Around 85,000 miles.
No CEL or flashing O/D light.
Stock except for the heavy 285 Nitto Terra Grapplers on stock suspension with 16 inch rims.
EDIT: Forgot he has a K&N air intake so not completely stock...

Sorry for the long winded post.
If you need to know something else, please ask.
I know a lot about my F-250 but little about this F-150.
I did a bit of searching but didn’t find much.
If you know of a post, please throw it my way.

 

I'm not sure I or you understand your shifting discription.
Third is OD off and can be with or without converter lockup..
Forth is OD on with or without converter lockup..
Only difference is the converter lockup feature. That is not considered a gear even through there is about a 300 rpm difference between on and off due to fluid slip when not in lockup in either OD or third.
There is not enough firm info to even guess.
Use of a good scanner to trap the fault or a good Ford trans shop tech that test drives and has some idea of what is happening.
It could even be the larger tires without program correction that is causing the marginal ****ing.
The tire size is data in the program that the shift sked references as well as th rear gear ratio, so it could be the cause as marginal at times to set shift load speeds because it's not what was expected.
Another feature you may not be awhere of is an auto response while driving.
If the throttle is let off, the trans may go out of 'lock' for a short time.
This is normal to help reduce braking distance under panic conditions so the lock up does not drive the truck but falls back to the unlocked soft condition of fluid slip.
After a few seconds if nothing happens the converter locks up again.
These are just some things to consider.
Good luck.

 

I thought this was a 4 speed auto with O/D so I guessed wrong.
Whatever the top gear is and involving O/D, that's the issue.
It high revs as if it briefly shifts to neutral when dropping out of O/D during acceleration but without any bad effects.
I don't know how else to explain but any bad understanding/explaining would be on my part.

You could be right about the tire size issue as nothing was recalibrated after he replaced the mini-van sized 245 tires.
At those speeds, the speedometer is off by 4 MPH.
I'm sure it will eventually end up in a transmission shop but I was asking here to gain a few bits of knowledge beforehand so he doesn't walk in dumb.
Or recalibrate first is the better route if it's possible.
Thanks.

 

the noise your hearing, i can bet is the serpentine belt slipping at the higher RPMs. every wide open throttle shift i've done with all my 5.4's and V10s over the years with a worn out belt will do this.. it slips alittle and sqeeks. new belt has always fixed it.

the shift issue without seeing/feeling it i dont know if it makes sense to me. normally when you drop out of 4th(o/d) into third its because you need more power, thus when it down shifts you'll have raised RPM's. but your saying it does it when your not on the throttle?

 

Add throttle and this will demand a lower gear.
It revs to 4,000 RPM for a second then shifts to a lower gear and runs at the RPM you would expect which is higher, yes.

Why wouldn't it simply downshift and jump the RPMs to 3,000 when more speed is requested?

That's why I explain it as if it's shifting to neutral for a second.
If the engine is at 2,000 RPM in o/d, I demand more power it should downshift and rev to 3,000 RPM with a lower gear not rev to 4,000 then quickly level off at 3,000 while still accelerating.

I may try to get a video of this for you. That's better than words.

 

Maybe the direct clutches are starting to slip. When downshifting from 4th(OD) to 3rd the OD band releases and the direct clutch applies. With the extra weight and high RPM the direct is prob slipping a little before it holds. Just my 0.02

 

Borrow a set of standard size wheels/tires to try.
It should rule out or in the tire size as a contributng factor.
.
In the software program, there are lines of instructions for how to handle transmission shifting either upward or downward.
The lines for upshifting and downshift are loaded with different values so the transmission is prevented from uncontroled hunting between gears.
Some think hunting takes place while towing in OD. It's not actually the case. The PCM and sensors involved make the shifting decision per load and speed.
Hunting would be 'uncontrolled' up and down shifting that never happens with the fault free system design unless there is a 'mechanical' fault or the loaded data in the shift lines of software were altered out of safe limits.. These data entries are called cross-over points.
Some who have tuners that allow this shift point data to be altered can get wrong values in place and cause hunting unless the after market software designer makes it impossbile to get into this situation.
My thought was the tire size could be contributing, so eliminate it by trying stock size tire as a test.
If it does not stop it then the trans has some marginal issue such as a sticky shift solenoid or broken spring in an accumulator etc.
Good luck with it, not much more to say until some work is done to narrow it down.
.