99 taurus speedometer and shifting problems.

I just bought a 99 taurus and while driving the speedometer will drop to zero and the transmission will start having shifting problems. This only happens when the engine has been running for a little bit though. Any help on how to fix this would be greatly appreciated.

Welcome to the forum!

It sounds like you have a vehicle speed sensor issue which will impact both the speedometer and the transmission shifting. I don't have a service manual for the 1999 model year, but in 1998 the regular Taurii had a vehicle speed sensor (VSS). The Taurus SHO derived the vehicle speed from one of the ABS wheel speed sensors.

-Rod

Thanks. I'll get the vss checked out. Is there neway I can test it myself?

The VSS is typically just a DC electric motor, the faster it spins, the larger the DC voltage it generates. If you can remove the VSS (usually on the upper rear of the transaxle) you could connect a DC voltmeter to the leads and spin the VSS with a drill to make sure it is generating a voltage.

-Rod