TH700R Trans Shifting prob

This question is prob gonna seem elementary to you guys with Trans exp.
85 Camaro, with TH700R trans. The trans shifts from 1st to 2nd when the speed gets around 30mph (I have no tac) sometimes hard some times soft but still noticable. Then shifts from 2nd to 3rd around 40-45, some times you notice that shift some times not, its softer than the 1st shift.
When comming to a stop sometimes you will feel it hit hard like someone bumped your car when it down shifts to a stop.
Changed Fluid and filter same prob. I noticed a 3 wire 4 prong plug on the drivers side of the trans. I disconnected and drove and had same results.
Any ideas before I burn the tranny up?

I'm not an expert on the automatics, but I do know that the wiring harness that you are referring to is for the vehicle speed sensor.
I would check the kick-down or throttle valve cable. Since the 700R4 does not have a vacuum modulator, it controls both upshift and downshift.

Yep that did the trick heres the link for anyone who has the same prob down the road.
Strange how it just decides to jump out of sinc, musta happened when I went to pass another car cuz it wasnt the same afterwards.

http://www.powerdemon.com/PowertrainPointersFEB03.html

Thanks for the direction and help MUCH MUCH appreciated!

I'm not an expert on the automatics, but I do know that the wiring harness that you are referring to is for the vehicle speed sensor.

For the TCC not VSS, his VSS is in the inst cluster behind the speedo.

indeed, thanks for the correction morley