Dodge Repair: 2000 Dodge Dakota transmission and speed sensor, automatic tranny, size trucks

Question
I have a 2000 Dakota with the 4.7 and automatic tranny. I scanned the computer and it told me the output speed sensor is malfunctioning so I replaced the speed sensor in the tranny, reset the light and after about 15 mins. it cam back on. I have since realized there is an ABS speed sensor in the rear diff. and after looking at it, realized there is a slight leak in the rear end. Even though the ABS light is not on, would this be the sensor causing my issues? After about 15 mins of driving, the transmission operates rough and it will not go into overdrive? Any help would be greatly appreciated.

Answer
On the full-size trucks I know that the single sensor on the top of the rear diff. is the ABS speed sensor and also used for vehicle speed.  Most of the time when the sensors fail there is no continuity between the sensor pins.  I've seen this on Dodges and just recently fixed a ford SUV with a new sensor as well.  I would start with a new one and clear the codes again.
Doug