Wow! Great site makes me happy to see and to know I have found a place to help me with my 2003 Dodge Durango SXT 4x4, great SUV but I call it my truck.
I'm 45 live in Atlanta Ga wife two kids two dogs a cat split level house that I will never pay off untill after I die.
I have read the threads about the ABS and brake warning lights, because this is the problem I am having,sounds like great info that I can use.
What I haven't seen is do these sensors cause the trans to not shift, and the one on the rear axel shoud it be leaking? because mine is, and it will not shift out of 1st gear.

 

First let me welcome you to my section.

Next, let's move your post to the right 1st generation section.

 

No, the rear one on the axle is not supposed to leak.. This one is the one that usually is the ABS light problem. The one that sits on the left side/rear of the tranmission is the one that can effect shifts. If it is not shifting out of first gear you may have bigger issues then this sensor. I would try the new sensor first but it sounds like your truck has entered limp mode, this is when the trucks computer has sensed a big problem and will only allow the truck to shift 1st and 2nd in order to get you to a safe place. This is safety feature that keeps the truck from getting a severely damaged.

Anyways, it sounds like perhaps you have 2 issues at least. one being the rear break sensor and the other possibly being the rear tranny speed sensor or tranny problems.

I would replace both sensors and let us know how it goes.