my 2006 f150 shutters or vibrates when it downshifts from overdrive
Thanks for the report.
If you actually have a question and want some speculation about it then include the mileage on the truck, the engine it has, and everything you have in terms of info about basic maintenance - things like spark plugs & wires, filters, and perhaps especially the history of transmission service. It would also be nice to know if you have actually done anything like checked the transmission fluid (level, odor, color), and what kind of driving this truck as done (e.g. a lot of load pulling…?)
It would also be good to confirm that we are discussing an automatic transmission. I’m just assuming that based on the mention of “overdrive.”