Randall1984

1995 Chevy 1500 2 wheel drive..350 throttle body engine, 4l60 trans... Sometimes the trucks speedometer won't work and the brake light comes on,the truck will shift from 1rst gear into 2nd, but when it goes into 3rd it's like it goes to neutral...But when the speedometer is working the truck runs fine. I changed out the speed sensor on back of the trans today and the speedometer now seems to not read correct & the trans seems to be going in and out of gear. The 2 wire plug had be rewired by previous owner, so I cut it off and replaced it again. Please help if anyone knows anything

greasemonkey47

Its been a while and I am not an expert on that transmission but there are a lot of automatic transmissions that also have a speed sensor inside the transmission that tells the transmission to shift. Usually though the sensor on the end of the transmission is for the speedometer the only 2 things I can think of as far as it not reading right would be either the sensor is the wrong one or the wires that are connected to it could be reversed. I wonder why it was originally modified? Years ago they used to sell aftermarket cruise controls that were connected to that sensor but I haven't seen one of them for a while. Hope someone has a bit more knowledge on that transmission that can help You. By the way if You have a friend that has a scan tool (not a code reader), It should be capable of telling You what the sensors are reading.