HELP!!![:@] I recently bought an 01 Durango RT 4x4. It will start to surge when shifting into overdrive and usually at low speeds and rpm's, (usually 35-40mph and around 1500rpm's). It also does this when cruise is on at highway speeds. Surging is only about 100-200rpm's. When I step on the gas, it acts just fine. It's like it doesn't know whether it wants 4th gear or overdrive. It won't do it all the time. No codes ever pop up. It's more annoying than anything. Other than that it runs great. First trans mechanic wanted to have the computer "flashed", but when he took it to a Dodge dealer, they said it did not need it. After that he was stumped. Second tranny mechanic thought the torque converter was going bad but first replaced the shift solenoid assembly, governor pressure switch, and a transducer switch,(whatever that is). He also told me there was no metal in the filter, and that was a good thing. Unfortunately for me, (and $500 later),it did not fix the problem. I found this forum, and after reading up, I myself have replaced the spark plugs, plug wires, cap and rotor, and TPS. I have also had the injectors and throttle body cleaned. No change. Now I am reading about an output speed sensor? Could that be it? I just hope this is a simple sensor or wiring problem and not a converter or tranny problem. Has anyone out there had this problem? I love the vehicle but would hate to have to spend a lot to rebuild the trans. Any advice would be greatly appreciated.

 

My tranny was acting weird, but only in the low gears. I replaced the output speed sensor on the transmission today and no problems. I have a 2000 5.9 4x4 and mine showed the p0720 code. The sensor cost $16 dollars and literally took 5 minutes to swap.

Mine also on a seperate incident , it did the surging while on cruise control. That issue can be fixed with the TPS. Maybe you got a bad TPS when you swapped it ?

 

Where is the output speed sensor located on the vehicle? Is that the technical term for it in case I go to buy one? I called Orielly Auto Parts in my city and the only sensor the guy told me about was an ABS speed sensor inside the wheel hub. I've read in this forum that it is on either the crankcase or rear axle. What does it look like? I wish my Durango would pop up a code. Never does.

 

The Output Speed sensor is on the drivers side of the transmission. Right under the trans, is a crossmember, it's right above that. Just look for a piece that has a wire going to it. Also the sensor has a molded 1" fitting on it, it's ridiculously easy to see. Here's the link http://www.autozone.com/R,APP1262557...ductDetail.htm

 

Go get the sensor, i'm willing to bet that is the problem

 

Hey Marine, just for the hell of it I went to Auto Zone and they do have the part. I stood there with it in my hand and decided not to buy it because I felt like I had been dumping money into it and just guessing. So when I got home, I crawled under the Durango, just to see where it was. You are right, it was so easy to get at. Then, for the heck of it, I unplugged the one on the trans and started it up. The check engine light came on. Then I drove it on the road to see what happened.

Guess what..............The friggin' thing ran GREAT!!!!!!! I am going to Auto Zone now to buy the new one. I'll let you know how it works out. Too bad a $16.99 part will end up costing me around $600[:@][:@]

 

Just got done putting in the new speed sensor. More fluid came out than I thought. Can this simply be added back into the dipstick? All seems to be o.k. Once in a while it still seems to surge ever so slightly(50rpm) but only in overdrive and it is hardly noticeable. Probably something else.

Stupid question: What would happen if you simply left the sensor unhooked? The tranny seemed to shift just fine without it. The only thing is the engine light stayed on. Anyway, thank you for your help. I really appreciate it.

 

There is also a sensor on the rear axel. Speed Sensor.

Other than that, I think a good cleaning of the TPS and IAC sensor on the Throttle Body could need a good cleaning.

Have you checked the Plenum gasket on the intake manifold?

Don't unhook the output sensor.

The surge could be on down hill slopes. Have you noticed?
If this happens than it is the torque converter going into unlock position. AKA torque management. If you want to see if it is this the problem then just hit the tow button on the freeway and see if surging continues. This locks the torque converter so no slip should be apparent.

 

To check the tranny fluid level, put your parking brake on, start it, put it in neutral to get a good reading if you need to add more tranny fluid.

Did you remove all the codes by unhooking the battery with the new sensor ?

If you ran it with the sensor unhooked i'm not sure what would happen other than the check engine light being on. But there has to be some kinda use for it, otherwise it wouldn't be installed on the truck.

Glad that worked out for ya

 

Actually, whenever it did surge was on an UPhill slope. Just before it would kick into4th gearfor needed power.Downhill slopes are fine and problem free, only uphill or slight inclines. I did check the fluid and it seemed fine, I just wasn't sure if the dipstick checked ALL of the trans fluid present in the vehicle, or only in the pan.Thanks for all your help.