Quote Originally Posted by GavL View Post
I believe the ABS sensors in the B-Series cars tell the car what speed it is doing
All they do is tell the Speedo and ABS what's going on. You have a BA ute, which uses the 4 Speed Auto transmission. The 4 Speed Auto takes its speed information from the instrument cluster, which is why, as you have no speedo, you have an erratic gearbox that has no idea what is going on. If the sensors are malfunctioning, so will the speedo, so will the gearbox.