blueskyflyer

My wife has a 99 Grand Cherokee Limited 4.7 which I believe has the 42RE. Recently, she had the “Check Engine” light come on and started having some transmission issues. Specifically, it has a loud “clunk” noise when shifting from park to drive. Once shifted into drive, it continues to act as if it is not in gear for a couple of seconds (step on the gas and it goes nowhere as if it is in neutral) but then engages and is fine. Lastly, it has lost overdrive. The switch seems to be fine as the light comes on and off but it just never shifts into high gear at highway speeds. The check engine code was a general transmission code (I believe it was P0700). All this seems to point to a serious transmission issue but I am hoping that somehow it may be something easier to swallow. I am not familiar with Cherokees but I have heard about common issues relating to the speed sensors and the governor pressure sensor/regulator. She has not been the best about changing the transmission fluid which I am sure has several years on it but the level does seem to be fine with no obvious burning smell. Based on these symptoms, I am hoping to have some advice and input so I do not have to take it to a local transmission shop and get completely screwed. Please HELP!!!

tsconver

you have a 545 transmission not a 42. You should take it to an autozone and see if their code reader gives you any specific codes. DId you do the key on off to get teh P0700? If autozone can not get you a true code then take it to a transmission shop or a dealer and pay their $50 diagnostic fee to get them to read it for you. THen you can decide on how to fix it.

blueskyflyer

I went to a dealer yesterday who told me it was absolutely impossible that these issues could be the speed sensors. I wanted a second oipinion so I went to another dealer who also assured me that there was "no way" it was the sensors, It was "obvious" that I had "major transmission issues" and quoted me $3005 (not including labor) for a rebuilt transmission built from Mercedes. I was almost conviced he was right but I went with my gut and he very reluctantly sold me the 2 speed sensors. I got under the truck this morning and had them both swapped in well under an hour. It would have been much quicker but I am the farthest thing from a mechanic and I didn't have any good light under there to see by. Regardless, quick and painless swap on the parts. Got back in the truck and immediately noticed the difference. The "clunk" was completely gone, there was absolutely no hesitation on engaging drive with power to the wheels, the shifts are like butter and overdrive is working fine.

Total cost: $78.54

Money saved: Many thousands of $$$

The call to the dealer who sold me the parts with an update that I will not be requiring his services or advice on repairs anymore: Priceless.

tsconver

Did the dealer actually drive it or hook it up and read any codes, even if teh CEL is off the codes will still be stored for retrieving? Wouldbe interested in knowing what codes were causing th eCEL to come pn. If not then he was covering his rear and giving you worse case.

Glad you got it fixed and it is always rewarding to do it yourself.

xtreme velocity

Congrats on the fix. I love that feeling. I had the same thing done to me when my brakes locked up. They tried to tell me it was my bearings. After all it was just mud in my brakes. Proved them wrong! I love fixing my stuff for cheaper than what they tell me to.

drakan1908

Glad to hear you got it fixed

BlueXJ

Good going bluesky. Glad you got it fixed and even more glad you did it yourself.