Speedometer on 1995 Ford Explorer

I just recently had a rebuilt transmission put into my truck which is working fine. But now my speedometer doesnt work properly. Sometimes when I drive it the speed shows accurately on the speedometer but other times when I drive it the speedometer stays on zero. Is this something that was casued by the replacement of the transmission or is there something different wrong with it? My transmission is under a two year warranty, I just want to find out if this is a new problem that can be easily fixed or something I will ahve to go back to the shop to have fixed? Thanks

1 answer
Go back to where the transmission was installed - sounds like a vehicle speed sensor issue, but it could be a wiring issue as well. Have the wiring and sensors rechecked.