Originally Posted by yardbird
The best way to road test for a TC shudder is as follows:
Get the truck to the speed and conditions that it shudders, and try to make it shudder as much as it will. When you feel the shudder, lightly tap the brake pedal, just enough to make the brake lights come on for a split-second.
This will make the TC unlock. If the shudder disappears, then it is the TC lockup causing the problem.
I have the same problem in my 95 t-bird with the 4R70W. If you just tap the brakes when the shudder starts, the TC will unlock and all is smooth. I then give it more gas to make it lockup at a higher speed and rpm.
Good point there. I just test drove an 03 Expedition, and experienced the shudder. What I did was manually turn O/D off, and it went away. I could not get it to duplicate the same shudder if I had O/D off. Where I was getting it to shudder was around 55 - 65 with a slight load, and giving it a little gas, but not too much to downshift. It also did it when I went down in speed from 70 on an offramp, then maintained around 55 for a little bit on the offramp.
The Expy has aroun 34K. Think it is a torque converter issue, or a fluid change. Do not know if it is original fluid or not.