Ran fine on Sunday and apparently had this problem all Monday. No check engine light so I have no codes.
2006 Jeep Commander 5.7L hemi. Works fine in 1st and 2nd gear (not in 4x4 low, I checked). As soon as it gets into 3rd gear the engine starts to rev but little power is getting to the wheels and it rarely upshifts. Plus the tach is really wonky and doesn’t match the engine speed but rather the speed of the car. It doesn’t like to show more than 2000 RPM and will even fall while I’m trying to accelerate. One time the needle jumped to 4500 and the car took off which is why I’m pretty confident that it reflects my road speed and not the actual engine RPM.
Really hoping its a sensor and I don’t need a new tranny. Oh and I didn’t find out about it until today and I didn’t get home until 11pm so I couldn’t really check the fluid level.
Basically if a car has a lot of mileage and the transmission is acting up, it is best to get it rebuilt. That is because it is a pain to remove it to work on it, so might as well replace ALL worn parts when it is pulled out.
Did you get a recall notice for your 2006 Jeep Commander for a transmission issue? There is one, might not be related to the problem you are having but it is worth checking with a Jeep dealer.
And there is a whole Jeep Commander forum that might be a better place to browse and ask questions.