mini-x fan

I have a 2007 King Ranch 4x4 with the 5.4 in it. I have had a shudder/bucking with light acceleration at 40-55 mph. If I turn OD off then it shifts fine for the most part. Well today on two instances I was coasting on the highway then went to accelerate and there was hesitation, then squealing and metallic banging sounds coming from under the truck, and then it bucked and shifted very hard. Does anyone have any idea what this is? It still runs fine with the OD off but I am thinking about taking it to a transmission shop soon to see if they can put an end to this. I just rolled 170k miles yesterday. Thanks in advance!

DarrinT04

good idea
good chance it needs to be rebuilt

SCORGE

The shuddering and bucking is probably plugs/coils...
The metallic sound, without hearing it, hard to say

DarrinT04

likely. i was about to say if there is shuddering and bucking in the transmission something is terribly wrong

BadFish523

This^^^ Most people on here come in thinking they have a transmission problem but in reality it is simply a misfire problem. Plugs and boots/springs will most likely fix the bucking.

arichens

+1 for plugs/coils. I had this exact issue on my '06 a few months ago. No DTCs on my scanner, so I took it to Ford, they plugged it into their computer and detected that it was arcing down the outside of the spark plug causing misfires under load. 8 new spark plugs later and the problem is gone! (If you replace the plugs, make sure you get the newer single-piece design. The two-piece plug design that these trucks shipped with are notorious for breaking off and getting stuck.

mini-x fan

I took it in today. They won't be able to look at it until tomorrow or Monday, but they believe it is my torque converter from what I described.

Stavros6517

Agree with Scorge that its probably coil pack - I had the same issue buck around 45-55 mph, stopped if O/D off. Took it to dealer and the diagnosed a cyl 4 misfire, replaced pack hasn't happend in 18 monts.

and I walked into Ford proclaiming that I had torque converter shudder but they disaggreeeeeed. dont get taken $$$$$

BadFish523

I would push them to check for misfires first. It is a VERY common problem with these trucks. See below, some reported back that plugs and boots/springs fixed it other didn't report back but it's likely they were fixed the same way also.

https://www.f150forum.com/f4/overdrive-shudder-431721/
https://www.f150forum.com/f4/5-4-triton-shudder-427128/
https://www.f150forum.com/f4/engine-shudder-426415/
https://www.f150forum.com/f4/help-tr...424380/index2/

mini-x fan

Y'all were right I have a misfire on cylinder 3. My plugs were replaced about 60k miles ago I'm not sure about the coils. Should I throw one coil in cylinder 3 and run it? Or should I go ahead and do plugs and coils on all cylinders? Any recommendations on aftermarket coils? I will be doing the work myself and have never done this before. Do I need to worry about plugs breaking if they have already been replaced in the past? Thank you!