I have a 1998 ford ranger xlt. My over drive keeps blinking and it shifts rough. How do i fix it?

I have a 1998 ford ranger xlt. My over drive keeps blinking and it shifts rough. How do i fix it?

There's sensor on top of the rear axle. Slowly remove it to prevent metal shaving from dropping back into the differential housing. Over time, metal shavings build up on that sensor because it is magnetic. Too much build up interferes with the pulse signal that commands the transmission to shift. While it's out use a magnetic pick-up tool and run it around inside the hole to get more metal shavings. You can clean the old sensor, BUT it is better to buy a new one since magnets weaken over time. After changing the sensor it is best to have the rear axle fluid drained and replaced as the old fluid will have shavings that will make their way back onto that sensor. Had this happen on my my old 2003 Ranger Edge, too. When I bought the new sensor the erratic shifting stopped.

If this doesn't solve your problem then the transmission needs flushed and a new filter installed.