Gillette1987

Quickly guys, I'm about to head to the auto store to do a "flush" on my auto tranny. 89 4.0 4x4 auto. Can't find the info on correct transmission fluid to buy and how much? Help???

Gillette1987

PO did the Jiffy Lube pressure flush for tranny. I've had issues with it since owning it for a month. Found out why it was shifting hard from 1-2 but still have problems. TPS/TPM and other electronics have been replaced/fixed but in 2nd gear going uphill, when I "floor" it, it slips horribly and doesn't down or up shift at appropriate times. This only happens on a steep incline. Flat or downhill it's fine. Giving it a shot with a drain/refill of tranny fluid. I remember reading somewhere about ATF being a big NO-NO but to use a specific tranny fluid. Help would be great, thanks!!!!

cruiser54

Maybe they put ATF+4 in it.

Get it at walmart: Dex/Merc trans fluid.

Have you ever done this?

https://www.cherokeeforum.com/f2/free-quick-fix-41821/

Gillette1987

I did that, PO somehow yanked the kickdown cable too much that it wasn't up shifting 1-2 and I'd have to let off the gas to let it shift... Did that same sequence you posted and fixed the shifting issue. Still not working for uphill climbs when I floor it

cruiser54

Tell me how you adjusted your tPS.....

And, have you ever done post 10 in my "Tips" link below?

Gillette1987

Cruiser, I've had the TPS tested and replaced with a dealership sensor, buddy of mine that owns a backyard shop and specializes in Renix motors did the sensor adjustment for me. He's a hard guy to get ahold of these days so I'm hanging out on this forum looking for answers. We ran the ohms and found them to be where it needs to be. Electrically everything seems to be fine, just not keeping up with uphill when I floor it... Bad rubbing when I'm flooring it uphill... I'm fairly positive it's the transmission fluid that's incorrect... Giving that a shot today and hopefully that cures my ailments
Update: PO just told me the oil change place used ATF-4

kgm

Buy a few gallons of the Diii/M fluid as if you're doing drain & fill, it's going to take a while to dilute it.

Gillette1987

I figured that. How many miles/time wise should I drive the jeep in between drain/fills? And how many quarts is it per change?

cruiser54

Sorry to say there is no "ohms test" on a TPS.

Use this:


RENIX TPS ADJUSTMENT

Before attempting to adjust your TPS, there are two things that need to be done.

1) 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.

2) With the Key OFF, and using the positive (red) lead of your ohmmeter, set on the lowest scale, 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.

TPS ADJUSTMENT FOR ENGINE ISSUES

Both RENIX manual and automatic transmission equipped XJs and MJs have a flat three-wire connector to the TPS which provides data input to the ECU. The three wires in the connector are clearly embossed with the letters A, B, and C. Wire "A" is positive. Wire "B" is ground. DO NOT UNPLUG THE CONNECTORS !! 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. Loosen both T-20 Torx screws attaching the TPS to the throttle body and rotate the TPS until you
have achieved your desired output voltage. Tighten the screws carefully while watching to see that your output voltage remains where it is supposed to be. If you can't achieve the correct output voltage, replace the TPS and start over.

Sometimes, after adjusting your TPS the way outlined above, you may experience a high idle upon starting. If that happens, shut the engine off and reconnect your probes to B and C. Start the engine and while watching your meter, turn the TPS clockwise until the idle drops to normal and then rotate it back counterclockwise to your desired output voltage.

TPS ADJUSTMENT FOR AUTOMATIC TRANSMISSION ISSUES

RENIX automatic transmission equipped XJs and MJs 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 outlined above—FOR ALL 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. THIS SQUARE FOUR WIRE CONNECTOR IS USED FOR TRANSMISSION/SHIFTING RELATED ISSUES ONLY. First off, DO NOT UNPLUG THE CONNECTORS !! Key ON, measure voltage between "A" positive and "D" ground by back-probing the connector. 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 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. The square 4 wire connector is just not used.
Revised 12-15-2013

belvedere

Doesn't much matter how much you drive between changes. Just run it through all the gears. You could drive it a few miles, or a few weeks.


Most people say 4 qts, but a few people, including myself, have only had about 2.5 qts come out when draining.

Gillette1987

Perhaps "ohms" was the wrong word choice hah. Buddy actually uploaded the same instructions and we followed it word for word as you posted. It DID help significantly with my previous issues

cruiser54

And you probed the "engine" side flat connector and used those values?

Gillette1987

Can't remember if we did or not...

cruiser54

You're screwed then...

LOL. The deal is that the TPS has two sides, totally independent of each other. If you test on the "trans" side, you will not find a problem on the "engine" side.

Gillette1987

Well when you put it that way, then yes we did