Yeah Fat_Mike, we sure been here before huh?

Thanks for clarifying Flyman, yes, try the vehicle speed sensor. It's toward the back of the trans on the Driver-side, plastic housing if I remember right. You will get soaked with ATF when you pull it out. There's a trick to not get drenched but I'm not going to suggest it.

It has like a magnet of some sort on the tip and metal bits can hang on there and mess up the signal. So, you can first try cleaning it real good and re-install and go for a drive. If that doesn't improve it buy a new one (from the dealer, not the aftermarket garbage) and try again.

Hopefully, that's the cheap way out.

After that, it gets more expensive and things have to come apart (solonoid pack). So, thanks for these super-reliable overdrive transmissions "Old Chrysler".