Transmission

[Big Bad]

I Have a 1997 jeep grand cherokee that I just purchased. I have a problem with the shifting of my tranny from 1st to 2nd to 3rd, but not all the time. It usually runs well, but sometimes, it decides to rev to 2800 rpm from 1st to 2nd, then 2200rpm from 2nd to 3rd. Then, it decides to shift well for the next little while. After a while, it does it again. Highway, it seems to run very well. Could this be a tranny problem, or what I heard from some people, a computer chip problem. Anyway any kind of help would be very much appreciated... thanks guys.

[dksob81]

yea it could be the CM (transmission comtrol Module). have u had the tranny fluid and filter changed this might help.

[dksob81]

TCM, sorry bout that

[trannyman52]

check the throttle valve linkage,,,,should be moving freely and smooth
returning,,, if not ,,,,,ya get weird shifts!!!!!

[dksob81]

yea it could be the TV cable but I would think if it was that it would happen more often, but a good thing to check, I think it maybe a sticky valve or soemthing, try changing the Fluid and Filter and add some LUCAS tranny treatment. that will halp any sticky valve problem u are having.

[Big Bad]

Originally Posted by dksob81

yea it could be the TV cable but I would think if it was that it would happen more often, but a good thing to check, I think it maybe a sticky valve or soemthing, try changing the Fluid and Filter and add some LUCAS tranny treatment. that will halp any sticky valve problem u are having.

I've already changed the tranny oil and filter, but it still does the same thing.. I;m going to look at the linkage, if not I guess I'll look at the TCM. What am I looking at price range for the TCM... Anyway, Thanks Alot Guys, It's great help!!!!!!

[dksob81]

I have no clue what a new one will cost but u can have it tested to c if it is bad.

[trannyman52]

the 1/2 and 2/3 shifts on that trans,, are a hydraulic shift {no electronics involved} other than a govonor signal ,,,,depending on the
vintage of trans,,,possible a hydraulic govonor signal,,,,,synthetic additives are ok lub guard or the like ,,,,,"conditioners" on the other-hand,,,, attack rubber components,,,,,,makes them like gummy worms,,,,,not good!!!!!!! dextron 5 or any synthetic ATF works too!!!

[msrjeep]

do not use anything BUT MOPAR ATF+3 on that transmission. there is no reason to use inferior aftermarket fluid. also, I don't recommend additives. Lucas changes the surface tension properties of the transmission fluid and can cause the fluid to foam up and this will cause more problems than it solves.

[photontony]

Can you change the CM (transmission comtrol Module) from outside the tranny. I am also having an intermittant shifting problem with wy 95 Grand cherokee Quadra Trac. starts out in 3rd with no overdrive. I can shift 2nd to 3rd Ok manually

[dksob81]

Yes u can change the TCM from outside the Tranny. but I recommend getting it checked at a Jeep dealership b4 u do. to make sure it is bad.

[dksob81]

u have a 42/44RE transmission, the TCM (transmission control module) is located underneath the Driver's side of the dashboard, to the left of the Steering Column.

remember to have it checked out to make sure it is bad, they are pretty expensive and I don't want u going and changing it, and wasting ur money if theres nothing wrong with it. if u need any other Info, let me know Joe [email protected]

[photontony]

I received your response and I thought you may have seen this problem
before. Here is some more scoop.
When the tranny is acting up it does the following:

1: Overdrive off light is always on and tranny will never go into overdrive.
2: Tranny starts out in third gear.
3: I can shift to second for starting out and manually shift to third, this
works fine and is the way I've been driving for a couple of days. the only
prohblem is that overdrive is not working and I turn 2800 RPMs at 60MPH
4: There is no slipping and tranny feels strong in 2nd and 3rd

Sometimes when I start the truck the tranny operates perfectly fine. Shifts
smmoth and correctly.

Last night I disconnected the battery and reconnected it to reset the
computer. This seemes to work and the tranny shifted fine for a few hours of
driving. This morning the tranny went back to the problem of starting in
third. I did check the fuses and they seem fine.

[dksob81]

well since resetting the computer helped with your shifting problem I recommend having the TCM (Transmission Control Module) Tested, and while ur at it have the PCM (PowerTrain Control Module) Tested. I am sure ur problem is in the TCM.

[Big Bad]

Originally Posted by dksob81

well since resetting the computer helped with your shifting problem I recommend having the TCM (Transmission Control Module) Tested, and while ur at it have the PCM (PowerTrain Control Module) Tested. I am sure ur problem is in the TCM.

I'm going to check my TCM on friday. Should I have My PCM checked, i was the one with the original message.... Thanks Guys, you've been great help