intermittenly won't shift out of first

cookie2 · #1 05-19-2005, 07:55 AM

My 1995 jeep grand cherokee 4x4 V6 with automatic transmission runs great but twice recently it would not shift out of first gear making it very difficult to drive.

I don't think it is the transmission. It probably has something to do with the vacuum system and sensors. Can anyone point me in the right direction? Is this a common problem? The car has 150K miles on it. The car returns to normal if allowed to set for a while. Shifting manually into first gear doesn't help. Does the problem have to be occuring when I take it to get it fixed for them to find it? Is there anything I can do to help diagnose the problem?

SteveB05 · #2 05-19-2005, 11:14 AM

There have been a few instances of this type...as a matter of fact, mine was doing something similar. I changed out the output shaft speed sensor and that took care of it.

cookie2 · #3 05-19-2005, 04:30 PM

Thanks Steve I will take a look at that, can you give me some more info on where it is etc.

SteveB05 · #4 05-19-2005, 07:32 PM

Its a sensor in the transmission just behind the pan on the lower left side. It's been over a year, but If I remember correctly, it was around $30. It just screws into the case, so no big deal to replace.

cookie2 · #5 05-20-2005, 09:58 AM

Do you know exactly what this part is called and where I can get it? Is it something you have to get from the dealership?

SteveB05 · #6 05-20-2005, 10:03 AM

It is called a "Transmission output shaft speed sensor" and I believe a dealer is about your only shot. You might find it at a NAPA.

cookie2 · #7 05-20-2005, 08:00 PM

Ok I bought a VSS sensor for the 95 from the dealer for $20 and it looks easy to replace, but my 95 is different from your 98. This is the only sensor I have on the outside but I read a post in here where some one was talkign about an output speed sensor inside the pan for a 94 which should be the same as mine. Anyone know anything more about this? I haven't replaced the VSS yet to see if this fixes the problem, but is there also a hidden OSS on the 95?

cookie2 · #8 05-21-2005, 08:07 AM

Well best i can figure out on the 42RE transmission there is only one sensor the transmission speed sensor as opposed to the two sensors starting in 1996. The part number for my sensor is equivalent to the ouput sensor for the 96 and above so I think I bought the right sensor. It looks easy to replace and only cost $20.

Hope this fixes it .. will let you know . The problem only occurs like once a week so may take a while.

SteveB05 · #9 05-22-2005, 06:07 PM

Let us know and good luck

cookie2 · #10 05-24-2005, 10:38 AM

Well we changed the output speed sensor, will take a little while to confirm a fix but so far so good. We also found some hoses pinched by a cover where the A/C drain is, I think they were coolant for the tranny. I don't think anyone has been in there which would mean they have been pinched since the factory. Maybe this was problem since it happened after things heated up. Anyone having intermittent problems after heating up might want to take off the cover where the A/c drain is and look for pinched hoses.

cookie2 · #11 05-31-2005, 10:50 AM

Well the Transmission output speed sensor didn't fix the problem. It still won't shift out of first gear intermittently about once a week. This time was driving some steep hills after driving for about two hours when it decided to act up. Let the car sit for a while and everything is fine. The first time the it happen the car was idling alot, and it happen one other time not sure why. The transmission oil has been changed but the bands were not adjusted. The output speed sensor has been changed. Anyone have any suggestions what to do next? Anyone had a similar problem? Do you think it is transmission?

cookie2 · #12 05-31-2005, 07:50 PM

Please help I am a poor college student

trannyman52 · #13 05-31-2005, 11:48 PM

check the throttle valve linkage from trans to engine ,,,,,,,,,,must return
to idle position,,,,if not,,,,it's calling for passing gear{no upshift},,,,,
if vss is bad,,,usually speedometer won't work!!!!!!!!

cookie2 · #14 06-01-2005, 01:03 PM

The speedometer works. So when this happens I need to look at the linkage? What would the linkage look like if it is not returning to idle? Is is easy to see? I am a girl who doesn't like to get greasy and I am away at college with little help. Will this return to normal once it sits for a while because the problem disappears after it sits? Or is it the TPS sensor? My bf says that it was shifting at high rpms sometimes before this problem started. TPS sensor? At 150K should I just change out the governor solenoid and sensor the TPS and the temperature sensor? Should I change the IAC what does it do? Tired of having problems .. sigh

cookie2 · #15 06-02-2005, 04:33 PM

somebody please help

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