F-150 Transmission Issues (I think? . . . No, I thought )

tpenfield

Moderator
Staff member
Joined
Jul 18, 2011
Messages
17,732
Greetings,

I have posted this topic in an F-150 forum and received some input, but not a whole lot. Since many of us are truck/towing aficionados, I thought to post it here.

My truck . . . 2012 Ford F-150 3.5 EcoBoost 4WD w/ 6R80 transmission, 206K miles.

I bought it in Nov 2021 for towing my slightly large boat the 1-2 miles from the launch ramp to my summer house. So far it has towed the short distance fine, and I use it occasionally for driving around, hauling larger items, etc. Since I've owned it, barely put 1,000 miles on it.

Recently, I have noticed a noise (seeming to come from the engine/transmission area) during moderate or hard acceleration. The best that I can describe the noise is a "pulsating screech' making quick screech noises about 2 times per second. If I back off the gas pedal the noise goes away.

I initially thought it to be the turbo(s) making noise, but then I realized that the tachometer jumps up/down about 300 RPM in the same pulsating fashion as the noise. This has shifted my focus to the transmission. At highway speeds it is a little hard to hold speed on hills, as the noise will start when I apply more gas pedal to maintain speed (60-65 mph). I figure the noise is not a good thing, so I try to avoid it by going easy and gaining speed before steep/long hills.

Driving around town is fine. The transmission shifts well at any and all speeds, but just makes the screeching noise and seems to slip if I use too much gas pedal. Entrance ramps to highways can be a challenge as that is when you need the most acceleration.

So far I have . . .
  • Checked transmission fluid level . . . OK
  • Added 'Instant Shudder Fixx' additive to tranny fluid . . . No improvement.
  • Changed tranny fluid and filter (MotorCraft OEM parts and Mercon LV fluid) . . .some improvement.
Although the fluid was old/dirty, the pan magnet had no metal bits and just a fine gray powder of metal dust around it. I figure it was typical for the miles (206K). Not sure of the vehicle history, since the truck has changed hands a few times before I bought it.

The transmission seems to hold better during acceleration after the fluid/filter change, but will still make the noise (and RPM slip) during harder acceleration.

Me thinks it is the torque converter on its way out, but the type of noise is not the typical 'shudder' that you would get with a torque converter problem. I've also read about a 'stator clutch' (one-way clutch in the torque converter) that perhaps is wearing out.

Any thoughts, experience, ideas, etc. are welcome & appreciated. 😀

  • Am I on the right track thinking it is transmission, given the RPM fluctuation along with the noise?

My plan is to drive the truck locally and use it for the few times to launch/retrieve the boat, while continuing to monitor the issue. Then, plan for the repair at some point. Just want to make sure I am on the right track.

Sorry for the long-winded post, but I am hoping to get some input (thank you!)
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
Staff member
Joined
Jul 23, 2011
Messages
47,661
changing the trans filter helps a bit as you get back to a sligthly higher line pressure.

however you may want to find a few more upholstery jobs to pay for a trans rebuild.
 

tpenfield

Moderator
Staff member
Joined
Jul 18, 2011
Messages
17,732
changing the trans filter helps a bit as you get back to a sligthly higher line pressure.

however you may want to find a few more upholstery jobs to pay for a trans rebuild.
Yes, I just want to be sure I'm pointing the cash cannon in the right direction. If a new torque converter will fix the issue, then I'll go that route for now.

I'm finishing the 'last' upholstery job for the season. I won't be actively soliciting business until the fall '23.
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
Staff member
Joined
Jul 23, 2011
Messages
47,661
Yes, I just want to be sure I'm pointing the cash cannon in the right direction. If a new torque converter will fix the issue, then I'll go that route for now.

I'm finishing the 'last' upholstery job for the season. I won't be actively soliciting business until the fall '23.
when a torque converter goes out, it takes out the pump assembly, which in turn causes the pressure to drop which eats up the clutches

im on 3rd rebuild of my 2014 GM (thru dealer) because they keep using remanufactured torque converters.
 

dolluper

Captain
Joined
Jul 19, 2004
Messages
3,903
It actually has a lock up torque that is applied in all gears... More than likely the tach movement is the lock up disengauging. Haunting for a gear Just driving it more often should help after fluid change
Do you drive it in tow mode when hauling ?
 

tpenfield

Moderator
Staff member
Joined
Jul 18, 2011
Messages
17,732
Thanks for the replies so far. I will check out the lockup clutch as I was not aware the TC had one.

Just wondering if the clutch is disengaging and re-engaging rapidly during acceleration, causing the noise and RPM fluctuation.

Not sure how harmful it may be. . . or not. :unsure:
 

tpenfield

Moderator
Staff member
Joined
Jul 18, 2011
Messages
17,732
In some quick reading last night about the lockup clutch, there should be a 'signal' valve (solenoid?) and a relay valve that activate the clutch lock-up.

I am wondering it the valve(s) are 'oscillating' during times of higher pressure (i.e. acceletating) giving the noise and pulsing sensation.

Rebuilt tranny's are $3500 ish, plus core, plus installation (beers).

I'll also check for codes, but no CEL is showing on the instrument cluster.
 
Last edited:

bruceb58

Supreme Mariner
Joined
Mar 5, 2006
Messages
30,481
Have you ever changed your transmission fluid and filter during these 200+K miles?

I change my ATF every 30K miles. I have the newer 10R80 transmission. First change was a pan drop and filter at 30K. AT 60K it was just a fluid change for the pan by pumping it out. At 90K will be another pan drop and filter.

EDIT: see you bought it used.
 

tpenfield

Moderator
Staff member
Joined
Jul 18, 2011
Messages
17,732
It looked like the fluid had been changed, but not sure about the filter. The magnet had no metal shavings just a very fine powder on it. So I assume the pan had been dropped at some point.

After having researched the function of the lock-up clutch, I'm thinking it may be the solenoid or relay valve being a little finicky, and the tranny going in and out of lockup during times of greater torque (acceleration). I'm going to give it some more time, and maybe add some SeaFoam tranny stuff to see if it frees those things up and then do a second fluid change.
 

bruceb58

Supreme Mariner
Joined
Mar 5, 2006
Messages
30,481
It looked like the fluid had been changed, but not sure about the filter. The magnet had no metal shavings just a very fine powder on it. So I assume the pan had been dropped at some point.

After having researched the function of the lock-up clutch, I'm thinking it may be the solenoid or relay valve being a little finicky, and the tranny going in and out of lockup during times of greater torque (acceleration). I'm going to give it some more time, and maybe add some SeaFoam tranny stuff to see if it frees those things up and then do a second fluid change.
Skip the snake oil treatment. Take it to a transmission shop who knows how transmissions work and have them diagnose it.
 

Redrig

Master Chief Petty Officer
Joined
Oct 13, 2009
Messages
849
hate to jinx your situation but your description is pretty much what was happening in my much older 91 Bronco with an E4OD transmission (fully electronic) . I was getting a code though about torque converter slipping. It would sometimes feel like I was driving on small rumble strips.

a transmission shop hooked it to a computer and while it was running they locked up the converter which should have killed the engine immediately. (like dumping a clutch in a manual)..... engine kept running just fine. meaning a full rebuild was needed.

hopefully thats not the case for you.
 

tpenfield

Moderator
Staff member
Joined
Jul 18, 2011
Messages
17,732
Thanks guys. I know that if I take it to a transmission shop, that they will just replace the transmission with a re-built one and about $6K later the problem should be solved. :ROFLMAO: If it was a daily driver, then that would be my best option.

However, I only use the truck a few times a year, so I'll give it some snake oil for now and run it until it doesn't. :D
 
Last edited:

tpenfield

Moderator
Staff member
Joined
Jul 18, 2011
Messages
17,732
Quick Update. . .

The snake oil (SeaFoam Trans Tune) is helping. The truck can hold speed on hills, but hard acceleration still gets the pulsating noise and slight tachometer upward movement.

I plan on changing the fluid again in the Fall; as I am using the truck occasionally this summer.
 

dubs283

Vice Admiral
Joined
Jul 27, 2005
Messages
5,179
FYI the 3.5 eco boost uses variable cam timing. Cam phasers use engine oil pressure to operate properly. Would think an engine fault could be present in this situation, however. Misfire, timing, oil pressure, etc.....

Quick check would be an engine oil/filter change, use a higher viscosity oil or slightly overfill to "poor man's" oil pressure boost?

.02
 

Harritwo

Chief Petty Officer
Joined
Oct 4, 2011
Messages
586
Ford issued a TSB for the 4 speed heavy duty trans in 2008 to put some anti shudder oil in it. Not sure if they have issued it for the 6 speed but it helped my 04 with a sticky lockup solenoid
 

tpenfield

Moderator
Staff member
Joined
Jul 18, 2011
Messages
17,732
FYI the 3.5 eco boost uses variable cam timing. Cam phasers use engine oil pressure to operate properly. Would think an engine fault could be present in this situation, however. Misfire, timing, oil pressure, etc.....

Quick check would be an engine oil/filter change, use a higher viscosity oil or slightly overfill to "poor man's" oil pressure boost?

.02
Interesting . . . So, you are thinking it could be the engine, not the transmission? I'll see what I can find out to see if that leads anywhere.

I did an oil change along with the tranny fluid /filter change.

I have the Actron OBD2 Code gadget . . . no codes.

I think my total annual mileage is around 2,000. The truck pulled my 14,000 lb boat/trailer rig down to the dock without a whimper. (going all of 30 mph :LOL: )
 

flashback

Captain
Joined
Jun 28, 2002
Messages
3,726
How about a junk yard tranny? 200,k is a pretty good run IMHO. I don't think I'd dump a whole lot into it...
 

tpenfield

Moderator
Staff member
Joined
Jul 18, 2011
Messages
17,732
The truck still runs and tows. I've been running the SeaFoam 'TransTune' stuff in it for the past month and driving it locally now and then.

It seems to be better, but will make the noise and tachometer slippage if I really accelerate hard. Probably will do another transmission fluid and filter change in the fall.
 

jimr

Senior Chief Petty Officer
Joined
Mar 21, 2004
Messages
723
Do you possibly have a loose clamp or torn boot on turbo line? poss. a bad motor mount allowing it to stretch the boot and hard acceleration. a leak in boost side will cause a loud screeching sound
 
Top