taylor_usmc72

what tranny should I buy? the stock one I have is pretty much done for. I don't know if I want to waste money rebuilding it.

Fallen

What are ur jeep's specs? And if you don't want to rebuild the tranny you could always go pull one with low miles from a junkyard

Bustedback

You'll find the low mileage XJs in the boneyard right next to the jars of unicorn teeth and magic beans.

Topjimmyk

Yea low miles and xjs r like oil and water. But the good news is the trannys can handle high miles as long as u keep them cool

taylor_usmc72

rookie mistake...i have a 96xj around 250000 miles. it shifts pretty hard and has takes forever to shift into 5th gear o the freeway, it will run at high rpm. it started this a couple months ago. i changed the fluid then it got worse. i know thats not necessarily a god idea, but i tried it anyways.

tjwalker

Two things to try.

1. Test your throttle position sensor. The input signals from that are DIRECTLY involved in how the AW4 shifts. More on that below.

2. Adjust your TV cable. A long shot, but should be tried. More on that below too.

Good luck!
--------------------------------------------------
The throttle position sensor is connected to the throttle shaft on the throttle body. It sends throttle valve angle information to the PCM. The PCM uses this information to determine how much fuel the engine needs. The TPS is really just a simple potentiometer with one end connected to 5 volts from the PCM and the other to ground. A third wire is connected to the PCM. As you move the accelerator pedal with your foot, the output of the TPS changes. At a closed throttle position, the output of the TPS is low, about a half a volt. As the throttle valve opens, the output increases so that, at wide open throttle, the output voltage should be above 3.9 volts. Testing can be performed with an electrical meter. Analog meter is best. You are looking for a smooth sweep of voltage throughout the entire throttle band. While slowly opening and closing the throttle, take note to the movement of the voltmeter needle. There should be a direct relationship between the needle motion to the motion of the throttle. If at anytime the needle moves abruptly or inconsistently with the movement of the throttle, the TPS is bad

You should have 5 volts going into the TPS. At idle, TPS output voltage must be greater than 200 millivolts. At wide open throttle (WOT), TPS output voltage must be less than 4.8 volts.. The best is to use an analog meter (not digital) to see if the transition from idle to WOT is smooth with no dead spots. With your meter set for volts, put the black probe on a good ground like your negative battery terminal. With the key on, engine not running, test with the red probe of your meter (install a paper clip into the back of the plug of the TPS) to see which wire has the 5 volts. One of the other wires should show .26V (or so). The other wire will be the ground and should show no voltage. Move the throttle and look for smooth meter response up to the 4.49 at WOT.

Perform the test procedure again and wiggle and/or tap on the TPS while you watch the meter. If you notice any flat spots or abrupt changes in the meter readings, replace the TPS.

The TPS is sensitive to heat, moisture and vibration leading to the failure of some units. The sensor is a sealed unit and cannot be repaired only replaced. A TPS may fail gradually leading to a number of symptoms which can include one or more of the following: -

NOTE: The throttle position sensor is also DIRECTLY involved with transmission shifting characteristics! It should be verified early in the troubleshooting process, when a transmission issue is suspected!

• Poor idle control: The TPS is used by the ECU to determine if the throttle is closed and the car should be using the Idle Air Control Valve exclusively for idle control. A fault TPS sensor can confuse the ECU causing the idle to be erratic or "hunting".
• High Idle Speed: The TPS may report faulty values causing the engine idle speed to be increased above normal. This is normally found in conjunction with a slow engine return to idle speed symptom.
• Slow engine return to idle: A failing TPS can report the minimum throttle position values incorrectly which can stop the engine entering idle mode when the throttle is closed. Normally when the throttle is closed the engine fuel injectors will be deactivated until a defined engine RPM speed is reached and the engine brought smoothly to idle speed. When failing a TPS will not report the throttle closed and fueling will continue causing the engine to return to idle very slowly.
• Engine Hesitation on Throttle Application: The TPS is also used by the ECU to determine if the driver has applied the throttle quicker than the Manifold Air Pressure sensor can read. The fueling is adjusted accordingly to cope with the sudden increase in air volume, however a faulty sensor can cause the ECU to ignore this data and the engine will "hesitate" when applying the throttle. In extreme cases with the engine at idle, a sudden application of full throttle can stall the engine.
• Engine Misfire: A fault TPS can report values outside the denied acceptable range causing the ECU to incorrectly fuel the engine. This is noticeable as a slight misfire and can trigger the misfire detection software and/or Malfunction Indicator Lamp (MIL) light on the dashboard. Extreme cases can cause excessing misfires resulting in one or more cylinders being shut down to prevent engine and catalytic converter damage.

-----------------------------------------------------------

Thread on adjusting the TV cable.
https://www.cherokeeforum.com/f2/free-quick-fix-41821/

taylor_usmc72

cool thanks dude

LYKOS

There are a lot of videos on servicing a tranny.

Just type "tranny video" in Google and you'll learn more than you ever wanted to know about trannys.

taylor_usmc72

haha with the jokes...besides I won't make that mistake again! just kidding

rompnXJ

of course it takes forever to shift to 5th gear, it doesnt have one!

that additional drop in rpm's after the 3-4 shift is the torque convertor clutch locking up. it will engage if load is low and the brake pedal is not depressed. pressing the brake pedal triggers the clutch to unlock.

xj_maniac_newb

if your buying a brand new tranny... i'd get a nv3550. 6 speed awesomeness However, i myself do not have that sort of money, so the junkyard is your friend.

taylor_usmc72

oh...i thought that was additional shift. well i feel like a newb. In my defense I dont know much about transmissions. But thanks. and now I know

taylor_usmc72

does that nv3550 come in automatic? Also where could I buy one?

salad

NV3550 is a manual transmission that came in some TJs and the 00-01 XJs. It's actually a 5-speed, first gear is reeally low http://www.novak-adapt.com/knowledge/nv3550.htm

Just find another AW4 from a similar year lol

Trev1006

The nv3550 is a good swap tho. It can handle alot of abuse. But its a project to do.