Johnthepanpire

I'm changing the trans fluid and filter on my 90 cherokee 4L 6i with a trans cooler.

My question is do I have to take off the cooler line to get the pan off? If so, where do I disconnect??

Kalali

Why take the pan off? What about just removing the drain plug?

cruiser54

Yes. If you wanna remove the pan you must disconnect the tube. But as stated why?

How bad is the fluid that's in there now?

jebmccall

he is changing the filter so the pan does have to come off.... i believe it is a quick connect to disconect the line at the pan though so it is simple. before you change it though how many miles are on youre trans/ last time the fluid and filter change?

cruiser54

It is NOT a quick disconnect. It's a PITA O-ring in a tube. Such a PITA that many people cut the tube with a tubing cutter and then put a piece of hose clamped over it when through.

Again, why change the filter if the fluid isn't trashed. The trans was designed with the "screen", not a filter, and to be serviced by drain and refill only.

maybe2fast

just a .02 suggestion...just do a drain and fill, then drive for a day and recheck color. If its still not satisfactory then repeat steps till color is owner satisfactory

Johnthepanpire

It's been around 5 years probably since the last trans oil and filter change .

The color is a clear, brownish red. No metal flakes or big debris.

cruiser54

Drain and fill as suggested.

Johnthepanpire

Good, I didn't want to pop that line off and probably break it.

I'll change and report back, thanks everyone.

jcarey813

dose anyone know if their is a transmission sensor under hood of 1990 jeep cherokee i preasurewashed under hood and now it won't shift unless high in rpms

cruiser54

Yep. The Throttle Position Sensor aka TPS. They do not like water sprayed on them.

You could get lucky and unplug both connectors on the TPS and spray them out with electrical cleaner and plug them back in. Don't get your hopes up though.

Chances are it's shot. If so, replace it and use teh following instructions to adjust it.

RENIX TPS ADJUSTMENT
Before attempting to adjust your TPS be sure the throttle body has been recently cleaned. It's especially important that the edges of the throttle butterfly are free of any carbon build-up.
IMPORTANT NOTE: With the Key OFF, and using the positive (red) lead of your ohmmeter, probe the B terminal of the flat 3 wire connector of the TPS. The letters are embossed on the connector itself. Touch the black lead of your meter to the negative battery post. Wiggle the wiring harness where it parallels the valve cover and also over near the MAP sensor on the firewall. If you see more than 1 ohm of resistance, or fluctuation in your ohms reading, some modifications to the sensor ground harness will be necessary. The harness repair must be performed before proceeding. I can provide an instruction sheet for that if needed.
MANUAL TRANSMISSION:
RENIX manual transmission equipped XJs have a three-wire TPS mounted on the throttle body. This manual transmission vehicle TPS provides data input to the ECU. The manual transmission TPS has three wires in the connector and they're clearly embossed with the letters A, B, and C. Wire "A" is positive. Wire "B" is ground. Key ON, measure voltage from "A" positive to "B" ground by back-probing the connectors. Note the voltage reading--this is your REFERENCE voltage. Key ON, back-probe the connector at wires "B" and "C". Measure the voltage. This is your OUTPUT voltage. Your OUTPUT voltage needs to be seventeen percent of your REFERENCE voltage. For example: 4.82 volts X .17=.82 volts. Adjust the TPS until you
have achieved this percentage. If you can't achieve the correct output voltage replace the TPS and start over.
AUTOMATIC TRANSMISSION: RENIX automatic transmission equipped XJs have a TPS with two connectors. There is a flat three-wire connector, same as the manual transmission vehicles have, and it is tested the same as the manual transmission equipped vehicles—FOR ENGINE MANAGEMENT RELATED ISSUES.
However, the automatic TPS also has a square four-wire connector clearly embossed with the letters A,B,C, and D. It only uses three wires and provides information to the Transmission Control Module. Key ON, measure voltage between "A" positive and "D" ground. Note the voltage. This is your REFERENCE voltage. Back-probe the connector at wires "B" and "D". Measure the voltage. This is your OUTPUT voltage. Your OUTPUT voltage needs to be eighty-three percent of your REFERENCE voltage. For example 4.8 volts X .83=3.98 volts. Adjust the TPS until you have achieved this percentage. If you can't, replace the TPS and start over. So, if you have an automatic equipped XJ your TPS has two sides--one side feeds the ECU, and the other side feeds the TCU.
FOR AUTOMATIC TRANSMISSION RELATED ISSUES. Check the four-wire connector side of the TPS.
If you have ENGINE issues check the three-wire connector side of the TPS. For those with a MANUAL TRANSMISSION--the TPS for the manual transmission XJs is stupid expensive. You can substitute the automatic transmission TPS which is reasonably priced.
Revised 05-28-2012

cruiser54

Good idea to replace the drain plug washer to avoid having a drip.

88_cherokee

because he wants to change the filter

cruiser54

See Post #9. It's not a filter. It's a screen. There was never a service interval to change it. Only drain and refill every 30,000 miles throughout the life of the trans.

88_cherokee

i know it is a screen. but again i g to the original post. he wanted to change it. i personally prefer either replacing it or cleaning it. does a transmission good.