You can probably tell that this really annoys me. Vehicle is a 99 Grand Cherokee 4.0 with the 42RE transmission. It has always had a 1-2 shift flare when cold where it would shift out of 1st into neutral and it would take about 5-15 seconds before it would shift into 2nd. Sometimes it would cling in 1st until 3-4K rpm before going into neutral and blipping the throttle might get it into 2nd gear after a few seconds. Not very safe when cold and driving from stops or hills but it would shift fine when warmed up.
I bought this Jeep more than 18 years ago at around 76K miles from a Chevy dealership in GA. Before my test drive the group of salesmen redlined the car to warm it up faster to hide the problem. From that experience, I will never buy another used car from a dealership again. It was sold as-is, and I drove it home out of state.
ATF+4 changes didn't help, I thought it must've been a faulty seal in the transmission or a pressure problem with solenoids or governor sensor. But I didn't want to take the transmission apart or throw multiple expensive parts at it without knowing the exact failure so I decided to drive it as-is until it fails. 18+ years and 180K+ miles went by and one day the trans seemed to start in 2nd gear and slip. It wasn't exactly in limp mode. It wouldn't shift into 3rd until at high rpms and releasing the throttle. I tried to drive it home and on the way it set a P0720 code: output speed sensor circuit.
According to a WJ website, it's a somewhat common failure among the early years of the model. Many years ago, I remember that I searched for the cause of the shift flare hoping it wasn't the actual transmission, I tested the trans output speed sensor with a multimeter which seemed to test ok. This time, I tested it and it seemed like it wasn't working. So I bought a new one from RA ($5 + $3 shipping). Replaced it and refilled a quart of ATF+4 that dumped out when removing the sensor.
Now, the trans shifts fine even when cold. After all those years, after all the wasted gas in neutral and high revs, after years of annoying drivers behind me expecting me to accelerate but the car's hanging in neutral, after time spent chasing whatever suggestions I found from searching WJ forums... it was an $8 part that took 5 minutes to change. After 18+ years and the Jeep has 260K miles still with its original transmission. $8 plastic part. Come on, Chrysler....
I'm disappointed it wasn't a more 'worthy' failure. That sensor only failed a little bit when cold and didn't fail completely so I couldn't trace the problem with my limited car repair experience. Most searches seemed to point towards a transmission seal problem. So, anyone else having shift problems with a 42RE car, consider the output speed sensor among your other suspects.
Any of you guys solved a long-term problem that turned out to be something stupid simple? Is there some way I could have tracked down this problem years ago before the P0720 code?
I bought this Jeep more than 18 years ago at around 76K miles from a Chevy dealership in GA. Before my test drive the group of salesmen redlined the car to warm it up faster to hide the problem. From that experience, I will never buy another used car from a dealership again. It was sold as-is, and I drove it home out of state.
ATF+4 changes didn't help, I thought it must've been a faulty seal in the transmission or a pressure problem with solenoids or governor sensor. But I didn't want to take the transmission apart or throw multiple expensive parts at it without knowing the exact failure so I decided to drive it as-is until it fails. 18+ years and 180K+ miles went by and one day the trans seemed to start in 2nd gear and slip. It wasn't exactly in limp mode. It wouldn't shift into 3rd until at high rpms and releasing the throttle. I tried to drive it home and on the way it set a P0720 code: output speed sensor circuit.
According to a WJ website, it's a somewhat common failure among the early years of the model. Many years ago, I remember that I searched for the cause of the shift flare hoping it wasn't the actual transmission, I tested the trans output speed sensor with a multimeter which seemed to test ok. This time, I tested it and it seemed like it wasn't working. So I bought a new one from RA ($5 + $3 shipping). Replaced it and refilled a quart of ATF+4 that dumped out when removing the sensor.
Now, the trans shifts fine even when cold. After all those years, after all the wasted gas in neutral and high revs, after years of annoying drivers behind me expecting me to accelerate but the car's hanging in neutral, after time spent chasing whatever suggestions I found from searching WJ forums... it was an $8 part that took 5 minutes to change. After 18+ years and the Jeep has 260K miles still with its original transmission. $8 plastic part. Come on, Chrysler....
I'm disappointed it wasn't a more 'worthy' failure. That sensor only failed a little bit when cold and didn't fail completely so I couldn't trace the problem with my limited car repair experience. Most searches seemed to point towards a transmission seal problem. So, anyone else having shift problems with a 42RE car, consider the output speed sensor among your other suspects.
Any of you guys solved a long-term problem that turned out to be something stupid simple? Is there some way I could have tracked down this problem years ago before the P0720 code?