2001 f150 Supercrew
120,000 miles
5.4 engine
Automatic tranny
4x4
Pretty much a stock truck


I just acquired this truck and so far she has ran great. I am getting concerned about the transmission though. At ~45mph while loafing along ( throttle at idle or just above) I try to accelerate very slightly, just to maintain speed, and the truck feels like it tries to up shift while the RPM is too low (~12-1400 RPM). The truck feels a bit like when you are trying to learn a manual tranny and let the clutch out a bit fast without enough throttle and the vehicle shutters a couple times before it smooths out. It only seems to happen in overdrive at a slow acceleration, with overdrive off or during moderate acceleration it is not an issue. I have noticed this also happening to a lesser degree at ~65mph under the same conditions. It happens pretty consistently and I can even make it happen under the right circumstances.

I am planning on changing tranny fluid and filter to see if this helps. I don't know if this is a mechanical problem or a computer problem.

Does anyone have any ideas or experienced this?

 

Was going through threads again and stumbled on one I missed that sounds just like my issue. Turns out it was ignition related, their problem was solved with new plugs and COPs replacement.

I will have to give it a try on mine and see.

 

Yes that where you should start. Maintenance. Motor craft plugs and coils. rock auto discounts that stuff. Change the transmission fluid to.

 

Did the new plugs and COPs solve the problem at all? I have the same problem with mine. Same year, miles, etc. Which thread did you stumble across that seemed to be the same prob?

 

I just finished with plugs and am waiting on COPs until i see if just plugs will do it. Plugs were in bad shape. Gap should be ~.054 and mine were .070 with a lot of carbon.

I will see if i can find the thread and give the link.

 

OD will kick in at speeds over 40 so dont be deceived by the convertor unlocking as you roll into the throttle

 

This was happening to my 07 took it back to dealer and they changed out the torque converter and problem went away.

 

This did not feel like anything I have felt form a normal running automatic tranny in the past and created a pretty severe lurching in the truck. I will hopefully be able to get out and test the new plugs soon. Hopefully it was as easy as that, we will see.

Here is the link to the thread that lead me down the plug/COP route.

https://www.f150online.com/forums/tr...-problems.html

 

Plugs; same thing happened to me around 120k. I went the tranny route and ended up wasting my time/money. Changed the plugs = smooth truck. Drive in tow haul until you get them changed.