Been there. It's on its way out. O/D Light is a dead give away. Soon it won't shift into gear, or into a higher gear like 2nd or 3rd. We have also had the late engagement problem when it went. Try the TSS I haven't heard of this being a problem before but I imagine it's a cheap fix if that is the issue. Our Zetec has had tons of transmission issues since the origonal died at 46K. It's been replaced 3 times. Rebuilt at least 5. Valve Bodies are the biggest issue. It may be you have deposits or buildups that are causing your issues. We have had a torque converter go out as well. The Zetec is again doing the soft shift on acceleration. I'm a bit fed up with it to be honest. If you get it fixed, do yourself a favor and find a post 2000 transmission. Or a new one if you can get it. While expensive it is your best bet to prevent future problems and you know the history on the transmission. I wish that I had done that in the beginning. I might not be having these issues again if I had. Best of luck.
