I've got the notorious t/c shudder in my 06 Lariat. I had the tranny flushed and refilled with Mobil 1 Mercon V full synthetic today and I still have the shudder going into overdrive. Any suggestions on what to do next? On a side note, I've s/c the motor along with a lot of other mods, so I expect a big fight at the dealership.

 

Can you remove the custom tune and reinstall it later? If so I would do that and remove the neg battery cable for 30 min. You will have to start and drive for at least an hour or more at a time several times a day for sometimes 2 weeks before your scanner will show = no codes found = and the PCM will be back to stock. That will make the dealer a little happier and if you can stand it drive the sucker 30 days and see if the shudder changes. There may be nothing wrong with your custom tune but with all this electronic stuff who knows.... might be some little glitch in the way the tune is shifting into OD. The PCM also stores some codes without lighting the CEL and that 30 days should allow the stock PCM to find those problems if any exist. Just a suggestion that might help pacify the dealer and maybe even shed some light on the cause of the shudder.

 

Probably ok to go back to the Ford Racing tune that came with the tuner for a short while, but definately not ok to go back to stock. I fear detonation! Besides, the shudder was there before I added any mods. I wish I was smart enough to get it back to the dealer before I started throwing parts at it. It's definately the the t/q converter. I can't seem to find a TSB on this problem even though I hear it's real common with the 04+ models, can anybody point me to the correct TSB. Maybe if I go into the dealership with the TSB in hand, I might not have as much trouble.