fast shifting
 

Why does my ranger shift normally (or what I think as normal) out of first, then shift all the way out to high really fast? It is more pronounced when I really get on it. It gets really annoying, it shifts into 2nd and then drive with less than a few seconds in between, it does not let any rpm's get built up at all,shifting to overdrive is normal. I have replaced tranny filter, is there a shift modulator that could be going bad? Any light shed on this would help.