wilkenms

Hey all,

So my 2000 XJ needs a new transmission, i have found several AW4s in junkyards in my area (baltimore) for fairly cheap. i have never swapped out a tranny on my own before, and was wondering 1. how hard is it to do (is it worth doing myself) 2. does anybody know any body in the baltimore area who would be willing to give me a hand with swapping it out. i have the 4.0 I6 and 4x4 with the NP231 TC. thanks!

dukie564

how on earth do you need a new transmission? How do you know it's bad?

mjonesjr

It is fairly easy to swap a transmission out.

Grab yourself a Chilton or Haynes manual and it will show you a step by step.

wilkenms

my jeep has 201,800 miles on it...in theory the tranny is OK, but the torque converter is bad ....due to check engine light fault code P0740 "TCC Soleniod malfunction" i have had all the soleniods replaced and it still trips the CEL. so, i figured it would be cheaper/easier to replace the whole tranny (since it has so many miles) rather than just replacing the torque converter. If you have a better solution, i am all ears. Looking for the BEST, but fairly cost effecient fix. thanks!

dukie564

it does have a lot of miles, but the aw4 is known for lasting well over 300k. So i wouldn't give up hope yet. Does it exhibit any shifting problems? What are your RPMs like at 70mph?

What actually sets off the p0740 code is the PCM "thinks" the engine's running faster than it should for these speeds, and that torque convertor clutch lock-up system could be bad.

I would try a few things first.

1. wiggle the electrical connector at the TCC solenoid. I've heard of people having this issue, wiggling the connector, and have the problem disappear. Try disconnecting it, inspecting the connector, and pack the connection with dielectric grease before reinserting it.

2. Check your transmission fluid level (tranny at operating temp, level ground, ENGINE ON) and condition (not burnt smelling or dark/cloudy).

3. Clean the throttle body and test the TPS. The TPS is a major player in how the transmission shifts, and could be causing the TCC issue.

4. The converter locks up in O/D- Look for the RPM to drop in top gear. Keep a steady pace driving at highway speed, then without taking your foot off the gas, tap the brake pedal just enough to light up the brake lights, but not slow the jeep down. The RPMs should jump up by a few hundred rpms. If it doesn't your converter may indeed be shot.

wilkenms

my tranny does not exhibit ANY shifting problems, ive had the TCC solenoid replaced and double checked by the shop that did the work (very good shop, highly knowledgeable and capable) first time they replaced it, the CEL came on after about 5 miles...after they double checked it, the CEL came on after about 150 miles of driving. transmission fluid, was flushed and filled by the same shop, level is normal. i will look into the throttle body and TPS. the lock-up works perfectly. RPM at 70MPH are about 2400RPM. That seems a bit high to me, but i don't know that much about the 4.0 and AW4. at 60MPH, the RPMs are between 1800-2100RPM. they dont jump around...sometimes they are just different (also something i was curious about) Any further guidance would be GREATLY appreciated.

dukie564

does not sound like you have tranny problems that would require it to be replaced then. Problem has to be sensor related.

Diesel

Those are normal RPM ranges, mind you it only has four gears and is not a race car. Get the problem fixed, dont fix it if its not broken.

wilkenms

redo of my previous post...i have one shifting issue...when i come to a stop at a stop sign or red light and sit for more than 5-6 seconds in drive with my foot on the brake...when i go to take off again...it feels like the transmission slips ever so slightly.

wilkenms

another question...my jeep is not my daily driver..i bought for the winters here in MD, and to have some fun with in the summer...if i don;t get this issue fixed right away...will it hurt anything else to keep driving it?

dukie564

nope

wilkenms

so, i had my TCC solenoid replaced and it seemed to fix the problem...for about 500 miles...now my engine RPM are a good bit higher than normal when crusing at 60mph (about 2400RPM at 60MPH) i cleaned the throttle body and checked the TPS, everything seemed in order. Any other thoughts, before i have a shop open up the tranny??