'02 issues

This is a great forum, thanks for all the info!

I have a 2002 Taurus SEL and man oh man -- this thing has been the death of me. The last time I was here (arouund this time last year) I had to replce the main chip plus light sensor and a whole load of other stuff. THIS year, so far it's been rear struts, idle speed control and some other things that I can't remember... it's getting expensive...

Here is THE issue that I can't seem to get my head around (nor that of my mechanic)... It seems that the tranny (sometimes) as I come to a stop at a light falls out of gear and stays out until I either rev the engine OR I can coax it back in by putting it in park and then in Rev and next drive. I cannnot find a common reason as to why this occurs, sometimes after driving a distance sometimes right after starting.

My mechanic suggests just replacing the tranny but I was hoping NOT to spend ANOTHER $1500 on the car if I don't have to ... after close to $7k over the past 3 years.

I was thinking that there is some electrical control that might be opening when the trans downshifts and keeps it from re-engaging. Of course.. I could be wrong, it's more wishful thinking! Any ideas?

Thanks!