My transmission started not shifting into o/d the would not kick down gears. Then the P0720 code came up. Done some reading on this forum and found the problem. I changed out the output switch on the trans. By the way got it from dealership. then tried to clear out the code it wouldn't let me, and the trans still not shifting right. Then I change out the abs sensor on the diff. got the code cleared but trans still not shifting right or kicking down. Any thing I'm missing?
Help please??

By the way I have a 2000 durango 4.7 4x4 with 15 bolt trans.

 

I'm sorry but I have bad news. This I have seen more than once and you more than likely have more of a problem than a sensor. I'm sure you didn't think of it when you replaced the sensor but it sounds like you are about due for an overhaul in your transmission.

It sounds like your torque converter is coming apart and sending metal through the system. It tends to send that code because metal flakes attach to the magnet on the end of the speed sensor and cause it to send a faulty code. Drive around and more than likely the code will come back, pull the sensor and look for metal on the end of the sensor.

If there is metal on the end of the sensor you have your answer and I'd suggest buying a rebuild kit and a new torque converter. I am sorry but this same exact thing and same sequence came from my transmission this is how I know.

Also, if there is metal on the end of the sensor, make sure you do the rebuild before you start breaking some hard parts. A rebuild kit and a torque converter is much cheaper than a sun gear and valve body and other kits inside the transmission that can go out due to problems internally.

 

Thanks for the info. That's not what I wanted to hear but at least I know . Did you rebuild yours your self? If so how hard was it 1-10. 1 being tire change 10 being motor tear down.

 

Yes I did rebuild it myself and it took a total of about 5 hours to do and I'd rate it at an 8. It's a very meticulous task and you have to make sure to get a good kit with all the seals you need. You have the 545rfe transmission so it's going to be a little harder finding the right kit you need but your best bet would be, if you indeed need to rebuild it, to contact the parts counter at your local dealership and ask for the part number for a 545rfe 4x4 rebuild kit.

Take that part number and shop around on eBay and various websites to find a decent kit. Good luck!

 

Thanks alot!!!

 

Ok I have been sitting thinking about this. If there was metal shavings-chips getting to the sensor why would that make the abs sensor on the dif go bad. it seems to me that after I change the output sensor it would have cleared the code up with that. Is there something else it could be?

 

It sounds like coincidence to me.

First of all usually when that ABS sensor on the rear differential goes bad it gives a "U" code in the system and triggers an ABS and BRAKE light to be illuminated in the dash, not a MIL. Also, the P0720 is an output speed sensor specific code. Many other codes are general codes but the code you gave is a very specific code.

After you changed the output speed sensor it would have cleared, had there not been more metal attach to the end of it, trust me I asked the exact same question to myself. Like I said before, just pull the sensor real quick and see if there's any metal attached to the end of it and you will find your answer very quickly.

That sensor is very easy to R/R! LOL

 

Well I think your right. Do you think I could get by with changeing torque converter and flushing system?

 

More than likely, probably. While the transmission is down on a bench I'd still tear it apart and check the clutches and make sure they're not damaged.

While the transmission is down run some cleaner through the lines properly instead of running a flush through the transmission itself. It proves to be much easier and a lot less dangerous in the long run.

 

Thanks aging for the help!