Hi!
I left my Jeep Cherokee in good condition last night and today surprise....
Transmission problem(in my opinion...hope I am wrong)
So...the problem is that the first gear changin is between 60-70Km/Hr., time enough to the coolant to ridge 100 celsius(after I drive ~10 km in 50K/h in town)
With other words, the transmission is working, but the first gear changing is to late.
I don't want to hear that I have to replace the transmission...Some idea?
Otherwise evrything is o.k., like transmission oil level...no leaking..nothing.

THX a lot.

First, it would help to know more about your vehicle. Cherokees span 20 years or so and have several different engine/transmission combinations.

The more info you give the better chance of finding help here.

What year? what engine? How many miles/kilometers on it, etc.? Is the shifting problem the same regardless of engine temp. <img src="/forums/images/graemlins/cheers.gif" alt="" />

Everything Pete said and also how long since a filter change? Have you checked the fluid level? Have you tried starting in LOW and shifting yourself to see if that works? Give as much information as you can muster.
Big JIm <img src="/forums/images/graemlins/pfft.gif" alt="" />

thank you for replay..so, it is a 1990 Jeep Cherokee, 4L engine, 6cyl in line, 220.000 Km on it.
Jim if you refer at air filter, last change was ~15.000 km ago.
The transmission oil level is between add and max, so is ok.
I want to mention that all this hapend after I wash the engine and under the car.
Can be the transmission speed sensor? If so, where is it?
The main sympton is that the first gear changing is to late(~60km/H)

Thx a lot.

tps sensor way have water intrusion <img src="/forums/images/graemlins/cheers.gif" alt="" />

No! I meant the auto tranny filter..
But You did give a good tip when you mentioned the water! I think I would get a hair dryer after it! You could park it in my driveway for a few days...Until today it hasn't rained ia a few months.
Big JIm <img src="/forums/images/graemlins/pfft.gif" alt="" />

You should have an AX-4 model transmission. It is electronicly controled but not completely. It does rely on information from the Throttle Position Sensor (TPS), A speed sensor on the transmission and a shift lever position switch, via the engine's computer or ECM, to tell the transmission controller, which is separate from the engine controller, when to shift. One thing you can do to see if it's an electrical problem or mechanical is to pull the "trans" fuse in the fuse box under the hood. There should be a ten inch long black box on the passenger side fender well that has the fuse inside it. You have to pull the cover unless it's missing It should be labled and there should be a map on the inside of the cover to tell which fuse is what. Make sure the fuse is not blown and don't forget to put it back in when you're done testing. pulling the fuse takes the electronics out of the picture and the transmission should behave as follows.

When the shifter is in the 1-2 position it should start off and stay in first gear.

When the shift lever is in the 3 position, it should startoff and stay in third gear.

When the shifter is in D position it should start and stay in 4th gear.

Reverse is not electrically controlled and should work normally with the fuse pulled.

In other words, with the fuse pulled, you should be able to shift it manually with the lever, starting in 1-2(first) then shifting to 3 (third) and finally D (4th).

If it behaves like above with the fuse pulled,the transmission is Ok and the problem is in the electrical control system.

If, on the other hand, the transmission stays in first gear when you start off in 3rd position(fuse pulled), then there is a mechanical problem within the transmission.

Now! If it was OK until you washed under the hood you may have water in the connectors between the transmission and the computer. They are on the passenger side of the engine compartment near the firewall. You can find them by following the wires up from the passengerside of the transmission (the neutral safety switch which is also the shift lever position and backup light switch) If you can find the connectors pull them abart and check for dirt and/or wet. It's also possible the TPS has a bad connection but that should cause other problems with idle speed being off or erratic if it is at fault. Likewise, if the ECM connections were bad from being wet/dirty there should be other signs with the way the engine behaves and the "Check engine" light would probably come on.

I recommend doing the test by pulling the transmission fuse. Then, if the test shows the problem is electrical,you should try to find the connectors I talked about and check them out.

I hope I'm not confusing you too much. Good luck. <img src="/forums/images/graemlins/cheers.gif" alt="" />

Pete,
I did the test by pulling the fuse.With or without fuse it's working the same.
I start with 1-2 than I swith to 3, than D, but the RPM remain the same.When I downshift to 1-2, I can feel the engine brake, the car slow down.
I cheked all conectors, they apears to be in good condition.
What do you think?
Thanks again.

The gear change is occuring too late 50 to 60 Kmph (31 to 37 mph). What happens after the late change? Does it shift through the rest of the gears after that? at 50 kmph it should be shifting into 3rd gear. When driving slowly, mine shifts into 4th around 60 Km.

When you did the fuse test, did you try to start off with the selector in 3rd or drive? and if so did it start off in first gear? Are you sure you pulled the right fuse?

Changing the transmission fluid and filter is part of regular maintenence and should be done, according to the factory manual, every 48,000km for normal driving and every 29,000km for severe driving. you'rs should be overdue for it's 4th filter change at least. The oil deteriorates and clutch and brake disk material normally collects in the filter and can clog it causing shifting and other problems. You should take BigJims advise, have the oil and filter changed in the transmissionand be sure they use the proper fluid type for Chrysler/Jeep transmissions. If that doesn't help you may be looking at expensive transmission repair work. <img src="/forums/images/graemlins/cheers.gif" alt="" />

I pull the Trans fuse 7.5.
I start in D, the first shift was at 60kmph thah I give gas and nothing hapend till 70-75, after I stoped because of coolant temperature.
Now I am going to buy trasm. fluid+filter.
I never change them,(2 hand car), so I am not exactly where is the filter.Wana give me a hand?(U already did..THX>)