Not sure what Automatic Tranny i have?

First I have to say that I have searched and searched and cant find anything on this.

I have a 90 xj Automatic 4.0 4wd. The selector on the console reads P R N OD 3 1-2, However that is not what I have. I have P R N OD D 1. Lowest selection is only first gear. Second selector is 4 gears like Drive. Then OD is 4 plus overdrive.

Very confused, lol. Is there something wrong with the transmission that is in there or could someone of swapped it out at one time.

Second problem. When in OD it LOVES overdrive. Anything over like 35 MPH it always makes it to OD. Then if im doing 55 and start going up a hill I have to almost floor it to get it to downshift. And if Im just going down the freeway and let of the gas then push it again it downshifts to 4 then shift back to OD right away. Very strange.

Any help would be awesome.
Thanks

• 1984 – 1986 : Chrysler A904 3-speed automatic, used with 2.5 L I4 and 2.8 L V6.
• 1994 – 2000 : Chrysler 30RH 3-speed automatic, used with 2.5 L I4.
• 1987 – 2001 : Aisin-Warner AW-4 4-speed automatic used with 2.5 L I4 and 4.0 L I6.

You have the Aisin-Warner AW-4 4-speed auto. Not too sure on your symptoms, but someone here should be along sometime to answer that.


Source:
http://en.wikipedia.org/wiki/Jeep_Cherokee_(XJ)

PIC:

Going in and out of OD is just the torque converter locking/unlocking and the 35 mph lock speed sounds about right to me. I'm no expert though... Since you have to really get on the gas to produce a downshift, I would first make sure your throttle cable is adjusted properly. There a little button on the end of the cable at the throttle body end. If I remember correctly, you just push the button in all the way and then push the gas pedal to the floor.

If you put the selector in the 1-2 position, you won't get that shift to second until like 4000+. So, unless you are getting the revs up, it will appear that it's first gear only.

not sure which one you got, try looking under there at the tags on the trans but.... you do not have to floor it to get it to get out of OD. Just tap the brake it will disengage the OD.. And 35mph is about where mine goes into OD as well and i have a AW-4. I am actually thinking bout putting in a switch to control the OD release switch that is attached at the brake pedal. That way I can effectively shut off overdrive in the hilly areas (like my whole way to work) and turn it back on and allow it to work normally the rest of the time. I drove it for a year with out OD so it will not hurt it. I found my switch wasn't hitting the brake pedal so I moved it closer and what do you know I had OD.

On the shifting, more than likely your Throttle Position Sensor (TPS) is going bad. Easy enough to test with a meter (preferably analog) and just as easy to replace.

Could also be the linkage cable is stretched, mine doesn't line up exactly

magimerlin said:

And 35mph is about where mine goes into OD as well and i have a AW-4. I am actually thinking bout putting in a switch to control the OD release switch that is attached at the brake pedal.

Click to expand...

The problem isn't with TC lockup its with the stupid OD gearing that is way too high for the low speed it likes to engage. I just keep it in 3 since that is essentially an OD lockout. I still get 3rd with TC lockup that way which is nice for around 45 mph, although much faster than that will cause the clutch fan to lockup (high RPMs) which causes temps to bottom out and MPG drops really fast.

Hey thanks for the replies guys. That helps a little. I have an extra TPS sitting here, it'll only take 2 seconds to toss it in.

As far as 1-2 goes i hadn't tried revving it out to see if it shifts to 2nd.
Also I wouldn't think that linkage would have anything to do with the fact that my 3 selection actually shifts 4 gears. Usually when i drive it I drive in selection 3 until about 55 then shift to OD.