Starting a while ago my tranny started slipping only on hard throttle. It won't do it into reverse and is fine with normal driving. I don't believe it does it on downshifts. Also, I can't tell if it's slipping, or just lulling between gears or what. It happens for a pretty long time though, about 1 or 2 seconds. I've adjusted the tv cable many times and that only makes it worse. It seems to do it into every gear, but once again, only on hard acceleration. I'm kinda stumped at this point.

 

Don't be stumped. It simply needs a rebuild.