Hi everybody, I have a 1995 Chevy k2500 6.5 td Vin F 4x4, with a recently rebuilt transmission the truck was shifting smooth until about a week passed and then it wouldnt shift out of first gear, I would have too shut it down and restart it and it would shift fine for several hours and the back to first gear only. I wanted to replace the input and output speed sensors and noticed that the input speedsensor was diconnected and that there was no connector for it, and I also saw that my wires going to the sensor on the transfercase were spliced and. I wanted to see if anybody new what the colors of the wires are from the input speed sensor and where they connect too?
Thanks

The input speed sensor is at the front of the driver's side above the shift selecter. The output speed sensor is on the transfer case. The output sensor on the trans. is not used if it's 4-wd. Have you connected a scan tool to check reading from the sensors? Have you cleaned ALL the grounds on the engine? The ones on the rear passengers side at the back of the intake manifold are the grounds for the ecm and the trans. Also check the main [big round] connector at the trans. for oil contamination. The wires for the input speed sensor are: grey/red and dark blue/white.

Thanks for the reply, the problem was that somebody pluged the connector into the output speed sensor, but that one is not being used. All the grounds are cleaned and checked.
Another question is that in the big round connector on the driver side bottom corner of the tranny was contaminated with transmission oil, not crazy contaminated but there was tranny oil there??????

If your're lucky ,the o-ring on the connector that seals it to the tranny case is leaking into the connector. Try cleaning with brake cleaner. If it gets full of atf again it could be leaking through the connector. I believe you have to replace the internal wiring harness to fix leaking connector. To replace the o-ring you have to remove the harness to get to it.