94 jimmy 4X4 auto trans, 2 dr

Well I have been trying to find out whats wrong with my truck shifting retarted only when my anti lock brake light comes on. If i unhook the ground cable to my batt for 1 hour or so. It will go back to normal. But after driving for half an hour. The light will come on, And my trans will shift funny / speedo will act up

I replased the speed sensor in the trans. No good.

Im out of idea's

Could this be a abs speed sensor?

Any imput? Thank you

2 or 4W ABS brakes?
Have you checked for abs codes?
Connect pin H and A and count flashes long and shorts and post back flashes.

Get it on a transmission/engine capable scanner and get engine and transmission codes and post back code no.
Also watch for the pcm for getting a good mph reading from speed sensor.
Post results back.
MT

For sure, like MT mentioned, check for codes. This though, sounds like it could be a speed sensor problem. If the speed sensor is not working properly, many funny things can happen, bad trans shifting, ABS problems, engine problems etc, etc.

I missed where you mentioned the speed sensor. While you replaced the sensor itself, take a look at the wiring and make sure its not damaged, or shorting out somewhere. Many times, when a transmission has been replaced/removed, the harnesses get damaged while the tranny is being removed or installed, and sometimes it takes awhile for it to pop up. With the ABS, bad shifting pattern, and especially the speedo, I am still in the speed sensor.

Speed sensor on a 4W is on rear of transfer case or rear end.
As said the wires may be bad.

Also we need codes and what you have 2W or 4W abs brakes
Also wiring is different for DRL or No DRL
And analog or electronic IP dash panel.

Keep in mind the speed sensor signal has to run threw a speedometer buffler and to abs computer and pcm/vcm to get to dash.
MT