I have a '03 F150 Supercrew 4x4 with the 5.4 triton V8 and auto trans.
In overdrive, at about 45 to 50 mph, if I'm lightly on the throttle, occasionally, I can feel a bump from what I believe is the transmission.

No problems in any other gear, no problems pulling steep hills in overdrive.
No shuttering, no slipping. Downshifts from overdrive just fine when pushing harder on throttle. Only does this about once a week now, has been more frequent in the past.

Seems to be a minor problem, but I want to fix this before towing my trailer again. Any ideas?
Thanks

 

How many miles on your spark plugs and coils?

 

Not sure. Probably quite a few. Truck has 188k.
Could this be the issue? Only occuring at a certain speed in overdrive?

 

Yes, what glc said.

Darrin

 

Low grade misfire. That's where it's first noticeable - light throttle right after shifting into overdrive. That's when the fuel strategy is the leanest.

 

Thanks for the info. guys. Does anyone have a link for replacing the coils and plugs and should I buy from local parts store or order from somewhere online?

 

Go Motorcraft.

Darrin

 

Get Motorcraft plugs.

Get your coils from ebay. I think Global and Uneek Auto sell them. You can get a whole set for what one costs from Ford and they are every bit as reliable if you read the threads on here.

A search will find you all the information on what to use and how to install it.