hoopdaddy6

Help is appreciated- I know next to nothing about transmissions.

my wife's (kinda) 02 Grand Cherokee Laredo- stock

Dealership serviced transmission about 40k miles ago.

Cruising on the highway between about 55 and 70 it will drop out of overdrive for no aparent reason. It is very annoying. Even when cruise control is set you can watch the tach go up and down as it shifts itself around. It doesn't want to seem to hold the last gear under even a little bit of torque (accelerating slightly, or going up a hill). Now I know when you accelerate or go up a hill it should downshift, but somethings clearly not acting right- it shouldnt be downshifting so easily or when you're just cruising. Checked fluid, and everything looks good and full and the right color. Not sure what would be causing this. All other gears act fine.

I think it's overdrive that's messing up, however when you hit the overdrive kill button, it shifts waaay down- further than when it does it on its own. You know what I mean.

Thanks for your help.

hoopdaddy6

17 views and none of you have ANY idea???

REWSTER

no idea

my wife's had shift solenoid problems but not like your describing

i hate the trans in thees things

trucker

It should shift in47mph to higher gear( that is what mine do). By default, the overdrive is engage when you turn the key on. When you start your car, press the button to disengage the overdrive and speed up to 50-55mph and then engage the overdrive. See what happen. I had that problem too and by ding that my overdrive started "beehive" correctly.

SpikeJr

I had simliar symptoms - crusing between 60-70 the trans would drop out of OD and the rpm's would jump up. Usually very brief, sometimes with a jerk in the vehicle as the trans would try to find itself.

I also happened to get a check engine light (CEL) and the code said the Thottle Position Sensor (TPS) had a problem. Come to find out the TPS sends signals to the tranny and that could be the problem. I had the light reset and drove for awhile...still had tranny probs, but the CEL didn't come back. I bought a MOPAR TPS since my mechanic said the aftermarket TPS sensors are hit or miss on quality. About 80 bucks for the TPS at the dealer and my mech put it in for $40. I had him do it since there are some minor adjustments and they have the correct computer to make it easier than me trying to use a volt meter to make adjustments...

End result is the tranny has had NO problems and is now smooth as silk...126k on the vehicle and I hope it keeps on going! Hope this helps