My Town & Country 07 shudders (best word I can use to describe the sensation) between 40-42 MPH. First repair place convinced me I need tie rods, $400 bucks gone, did not resolve problem. Next place said I need struts and new tires. $1600 gone and the problem is not solved. Anyone out there have an idea why the van would do this shudder, rumble, whatever - but only at 40? If I rapidly accelerate, like getting on the highway, it doesn’t happen. Many thanks!
Sounds like the lock up clutch is causing problems. There are several additives that are marketed just for that problem but if the transmission is due for service take care of that first and see if the problem is cleared up. I would recommend getting the pan dropped and filter replaced rather than the flush treatment.
I think you need a competent mechanic. It sounds like the places you’re going to are guessing poorly and throwing expensive fixes at it to see what sticks. They are not even making educated guesses.
TSB # 21-015-07 involves a software update and replacing the torque convertor to address torque convertor shudder on this vehicle.
If the wrong automatic transmission fluid was used in this transmission you should first replace it with the correct fluid, Mopar ATF+4.