2006 5.4 4X4 Tranny issue
 

This is my first post. I've had a lot of trouble with this truck. Bought it w/125,000 mi. It had a dented drive shaft that caused a lot of vibration. I originally thought it was the tires. Replaced drive shaft and ok. Replaced transmission fluid and filter at 130,000 mi. Had to replace upper and lower ball joints at 140,000 mi. At 175,000 mi I noticed a shutter after changing into overdrive and running in overdrive at low RPMs 1500 to 1800. At 178,000 mi the limited slip clutches along with a bearing was going bad so I replaced the rear end with a used one w/ 62,000 mi on it. Rear end problems are gone. Still had shutter going into overdrive and noticed that it now doesn't always go into reverse when I switch from drive to reverse, but if I go into park and then reverse it works. Still have the shutter issue and since the plugs and coils had never been changed, I had that done. Truck runs a lot better, but still have the shutter in overdrive. Any suggestions?

What brand coils did you buy?

And what brand plugs?

Still have issue with misfire that I thought was cleared up. Last week I had a misfire on cylinder 5 under heavy load after the coils and plugs were changed, so I swapped the coil on cylinder 5 with the coil on cylinder 7. Yesterday I had the same thing happen and it is still cylinder 5. I'm thinking now that it is either the new plug or the wiring going to it. I need to mention that I'm calling the "heavy load" when I hit the accelerator really hard, not floored, but hard, then it downshifts and the RPMs go to like 4000 and after a few seconds of that the misfire happens.

They are Ford Motorcraft coils.

They are the Champion one piece plugs.

Pull the Champions and put Motorcraft SP546 in.

I just saw your reply. I bought another Champion plug for cylinder 5 yesterday and put it in. The plug I pulled out looked like it had been in for more than 5k miles, but I know it hasn't. I tried it this morning and still getting a misfire. I didn't have a scanner hooked up at the time, but I'll check it again to see if cylinder 5 shows up. I've got a couple of more things I'm going to try before I swap out all of the plugs since I seem to only be getting a misfire off of cylinder 5. Thanks for the help.