98 trooper purchased a few years back with 140K mi on it. Love the vehicle! the leather interior is great with kids and muddy farm trips, the push button TOD is great for most of my off-roading and she tows great, I have had no problems except oil usage. Today she has 160K mi and is exhibiting a transmission problem.

I was driving in to work and stopped at a traffic light, everything was normal; when i pulled away the car was very sluggish and did not shift even when i got up to higher speeds. since the engine was not revving real high i figured that I must be in a higher gear. I tried dropping out of D in to 3 and no diff. so I tried dropping into 2 and it was a bit better. Dropped in to L and take offs were normal.

When starting from L and manually shifting to 2 the engine swamps down with a pretty big clunk in the transmission and then syncs with the road speed and is like normal, if I shift to 3 then i get a normal shift up shift to 3rd gear, if I shift to D I get no up shift to 4th/ OD
while driving around 35mph I can shift to 2 and get a down shift, if I shift back to 3 I get an up-shift. While in 3 if I fully depress the accelerator I do not get a down-shift.

I dont think the transmission is shifting (up or down) on its own. there is no noise or leaking or funny smells. and it is not in "winter" mode.
I went to a transmission shop within 30min of the event and they said to come back Monday, it is OK to manually shift for the weekend and that it might be a fuse, wire or solenoid but probably not mechanical.

I dont know enough about automatic transmissions to diagnose on my own, maybe the mechanism that causes a shift has a bum pump or seal, maybe a bad solenoid or relay? anyone got some tips that I can try over the weekend???

thanks in advance

 

As an update:
I got on the JustAnswers website and posted this same thing. the mechanic that replied to me thinks it is the valve body. I think he said "blow valve body" to be precise.

funny thing is, when I got to my trooper at the end of the work day it cranked right up and drove like NORMAL!!! It did not dawn on me that I had left the car running while talking to the mechanics. maybe it was just a sensor or CPU malfunction, not sure. I will still take it to the transmission guy to have it diagnosed (he said he would do that for free) until it happens again I cant say weather this is the beginning of an intermittent problem or just a fluke.

I will keep you posted