I thought my tranny was going out when I heard a loud whirring noise that sounded like it was resonating up between the cab and the bed. Turns out that was my bad pinion bearing in the differential. That is what led me down the road to fixing everything.

The stutter is still there though and having read all of this I don't think it is the trans either???

 

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I am having this same exact problem with my 2004 f150, but I also can't give you any tips because I am a girl and don't know much about mechanics so If somebody knows what to do please tell us

 

If you hold your foot steady will it eventually stop shuddering?

 

I got the same problem as you guys. 60 - 70 mph. goin down a hill or something elese that causes me to apply a very light throttle I get a shutter. If im giving a lot of throttle or none at all it doesn't shutter. Im thinking pinion gear (ive lifted my trick 5 in front 3 in back) is shifted. OR the COPs or Plugs. Let me know what happens to yall, especially riverracerx!

 

Here are the symptoms that I had with my truck before I changed my spark plugs. 1) When going down a hill in cruise control, the truck would shutter once the engine had to re-engage to keep the speed up. 2) Driving on the highway at a constant speed (40-60 mph) and slightly depressing the pedal to speed up, it shuttered. 3) When speeding up (in #2) the gas pedal, and sometimes the truck, would groan and slightly vibrate. 4) Shifting was sometimes hard/rough between gears.

Turns out all of these had to do with ignition issues. Changed the spark plugs for the first time (PITA btw) and all seem to have been resolved. The truck still vibrates a smidge when driving on the highway but I think that may be due to it have 145k+.

Hope this helps and good luck with the plug change. One of my COP's went bad right after I did the plug change (weird) and gave me a seriously rough idle. Threw check engine and found out it was the COP and the plug had been fouled. Changed out and now drives great and idle is pretty good.

 

and when I say shutter, I mean more of a skip. Poor word choice, my mistake.

 

I had the exact issue when I bought mine. It IS a faulty COIL OVER PLUG causing the around 40 mph shudder. Change them all and you will feel like its a new machine trust me.

 

hey yall, i had the same problem. weird shutter at highway speeds when not accelerating. then i took a 7 hr trip and made it 4 hours before it started REALLY shuttering at those speeds. (i had a washer and drier and other cargo that probably provoked the excess stress) and by hour 5, i couldn't go faster than 30 mph. terribhle. took it in and all the guy could tell me was that my system had a HISTORY of a misfire in cylinder 8. So i bought a COP coil and put it on that cylinder and nothing changed. so then i went ahead and replaced that spark plug as well and now she's runnin like a champ!
Now my plan is to go ahead and replace all the spark plugs, and if i get a problem again, ill know its the COPs. Good order to do it seeing as to how those things cost 53 bucks a pop.

Moral of the story, go ahead and replace all the spark plugs and see what happens. if it still acts up, just wait until your engine throws a CEL and have it checked and youll know what cylander to replace the COP on

 

That will not hurt anything. It is called the tow tune only because the pcm is tuned to run the engine a little more rich and the shift point rpms are lower.

 

Just to clarify. So you guys who had a shudder/skip between 45-65mph, just cop's and spark plugs and now the truck runs perfect?

I have this problem on my new to me 05 king ranch and im ready to throw A new tranny In. Can't stand this shake, so embarrassing.

 

I did this and now my F-150 feels great. It seems to have more power and the throttle response is better.
I used the yellow Accel SuperCoil packs. Our local parts store did an internet price match, $185 for the set of 8.
I'll follow up if there is any change in the mpg.

 

I have a problem in OD going up hill and going into passing gear the tranny shudders on the interstate if I get into the gas hard it stops any ideas would be great!!

 

Change the transmission fluid.

 

I have 04 5.4, replaced plugs 20,000 miles ago and have same problem, shutter between 45 and 60 mph. truck is parked but I want to fix asap. does anyone have any idea that isn't a $1500 fishing expedition.

thanks,
Mike

 

Coils. Did you replace the boots and use dielectric grease when you changed the plugs?