Some time ago, I started noticing poor shifting (sometimes no O/D downshift), a vibration/shudder under my feet (my assumption is the torque converter) and an occasional failure to shift into neutral when braking.

After describing the symptoms to my mechanic, he called his transmission specialist and we went to work. We flushed/replace the fluid with Mobil 1 ATF, cleaned the pan/magnet (both were very clean), replaced the filter (again very clean), added 2 ounces of Lube Guard shudder guard, and replaced solenoid #1 (shift) and solenoid #3 (can't remember the name).

The transmission shifts very smoothly now, and feels as good or better than it ever has. All symptoms have disappeared, except the shudder. The shudder is greatly reduced (from a "10" to a "3-4"), and really seems to mostly occur when it is cold and right before a shift. I was told that the torque converter may just be beginning to fail. Since the Lube Guard had a noticeable affect, I was wondering if I should add another tube.

If the torque converter is failing, it will need to be replaced. I suppose that that would be "major surgery", and wonder what it would cost. My knowledge of transmissions is obviously limited, so any knowledge/information/insight would be greatly appreciated. Oh, and Merry Christmas!

 

In a 4x4 I 'm sure it's costly, have no idea how much. Would be a good time to install a performnce converter from B&M or someone. Make your 4x4 rock and roll in the dirt.

 

Do you think a faulty TPS could cause these symptoms?

 

I'm clueless on these sensors, if I get a code, I take it to ford.