I have noticed an interesting situation with my Suburban... the transmission "coasts" like it's in neutral when you lift off the throttle at highway speeds. I had read that this is a condition that exists when the TV cable is too loose. So I re-adjusted my cable in the usual way: pressed the button on the cable and snapped the throttle open, the cable snapped into position. I held the throttle wide open and checked the cable, and it was guitar string tight. So then I test drove it. It shifted fine, just like before. Shifts were right on time, firm but not too hard, and it felt good, until I lifted off the throttle and the transmission coasted like I was in neutral again; the engine returned to idle at 60 MPH. I manually re-adjusted the cable tighter one click at a time until it stopped. This took 4 clicks. Once I did that, the transmission stopped coasting when I lifted off the throttle, but the transmission was holding the gears too long, the shifts were harsh, and you can't so much as breathe on the throttle pedal and it drops out of overdrive. Also, If I floor the throttle, the cable snaps back to it's "properly" adjusted position, and then the "neutral" coast at highway speeds returns. The transmission will re-engage with slight throttle pressure. What can be causing this?