As Viktor mentioned, if the valve itself is stuck, it won't shift at low rpms because the valve is telling the transmission you're at higher open throttle. IF it's the cable that is holding the valve open, then disconnecting the cable should let the valve go back to idle position. No you may not feel binding in the throttle. If the cable is holding the valve open, you won't feel it at all.
Remember, the TV valve also regulates fluid pressure on the 700r4, higher throttle, means higher fluid pressure. So if you do disconnect it, then you need to drive it with only light throttle take offs and such, because without the higher fluid pressure holding the clutch packs tighter, they will slip, overheat and trash the trans in short order. With slow gradual take offs and slowly building speed you may be OK.
But what if it is just a stuck TV valve or bad cable? What if changing the cable or freeing the stuck valve fixes the problem and you don't need a complete build? Did I miss something or forget something buddy? The trans isn't slipping now right? Just having shift point issues right? How does the fluid look now? Is it pretty red or a tad dark red? So long as it's not dirty brown or burnt, new fluid most likely isn't going to hurt a thing and might help. That myth that new fluid kills transmissions is only on wore out or poorly maintained transmissions. It's that most people when they start getting a slip issue, they think changing the fluid will fix it, and in fact it kills what little is left in the transmission. That is true. But if you current fluid is mostly red and not a burnt brown or black I'd say the new trans fluid is going to be just fine.
So if you need to drop the pan to the check the TV Valve and/or replace the cable to fix the problem, then go for it. It would be great if a new $20 cable fixed the problem and the trans is fine.
