Testing and Replacing AW4 trans solenoids

[awg]

There are 3 solenoids in the AW4

If solenoid 1 fails, your trans will have not have 1st or 2nd when in D

If solenoid 2 fails you will have no 2nd or 3rd when in D

Solenoid 3 controls the Torque convertor

If your trans has these faults, it is possible to diagnose and repair yourself

t is advised in FSM to disconnect the TCM plug, and drive it manually,as well as conduct tests from that plug

You can instead use this 7 pin plug



disconnect and the the solenoids are disabled and can be checked with a multimeter, should be about 12-15 Ohms

measure between battery negative and each of 3 female terminals..check FSM (8W-31) for correct wire colors for your year model

If no good, remove trans pan and check solenoid resistance itself

the clips are super brittle, be as gentle as you can, (if they break, they still work)

one 10mm bolt removes the fault solenoid






closeup shows TC solenoid 3 with a pin as backprobe,





see this writeup from GoJeep how to manually activate solenoids so that you can manually lock 2nd gear, or TC

http://gojeep.willyshotrod.com/HowtoAutoSwitch.htm

draining the pan is a bitch

be ultra careful with the 19 pan bolts, they strip the thread out of the female holes in the trans like butter

[alexbrown64]

Good write up Tony.
At 325,000, my AW4 runs great, but one day it may start playing up.
I did a service on mine, and draining the pan was easy as I have a drain plug. A new rubber gasket and just nipped the bolts back up, and she has never leaked.

Cheers,

[awg]

Originally Posted by alexbrown64

I did a service on mine, and draining the pan was easy as I have a drain plug. A new rubber gasket and just nipped the bolts back up, and she has never leaked.

Cheers,

the bitchy part is not spilling any fluid, (like all trans pans)

I leave 2 adjacent corner bolts, and lower them last so the excess fluid
can spill over the corner

the solenoids do fail eventually, but its a very easy fix

not hard to diagnose either

its advantageous the AW4 can be operated manually without solenoid control

[Mudgee hunter]

Kool, I saw a clip that said the middle/ 2nd solenoid was often the culprit of failing due to heat.

[Browneee]

Evening guys…

Just stumbled on this thread at a timely fashion as my AW4 started playing up last Friday.

I had a new filter which I purchased for an XJ I had prob ten years ago and never installed (I’m on my 3rd XJ). So on Saturday I dropped the oil, changed out the filter and flushed the system. Then adjusted the kick down….

Problem still there…

So when engine gets up to operating temp when I come to a stop at the lights etc it won’t shift down.

Shifting the lever into 1/2 no problems takes off as normal. Shift into 3rd again no problem and then D no problem. It just won’t down shift on its own.

So I’m gathering it’s the solenoids… have no problems changing out all three as I’m sure it’s never been done before on my old girl (96 model and I’m not the first owner and with 277k on the clock)

I do have a couple questions though…

One.. can I keep driving it simply shifting down gears at the lights until I get some new solenoids ? (First time I’ve had this issue on any of my XJ’s) do I need to disconnect the TCM plug asi think the original poster of this thread wrote… and if so where will I locate this plug hahaha

Two.. the 1/2 position on the gear lever, when you take off at the lights it should takeoff in 1st then shift into 2nd and hold 2nd yeah ? Mine does not… it holds 1st then select 3rd and it drops into 2nd the 3rd…

Can someone correctly describe the shift sequence? I know this may sound stupid I just want it correct in my head as it’l help me diagnose and I also tow a boat with it as I have down with my other two XJ’s previously.

For some reason my XJ never suffers from heat problem’s like my other previous two which is a god send. I do plan on putting an after market tranny cooler on, did this on both previous XJ’s as my boat is around 2 ton max.

And three… can any one suggest where I can buy the solenoids for the AW4 ? I’ve emailed my local jeep parts guys Dave at Jeepspares in Wa, I’ve seen some on eBay ?

I’m in Perth by the way and yes I have the 4.0

Regards Rob

[awg]

follow my instructions in the 1st post to diagnose if a failed solenoid is your problem

its the upshifts that prove it out, then measuring the resistance of the solenoids

download the free FSM from the USA website to get to wire colors for your year or Google search

the solenoids are available from Ebay, maybe USA Ebay, but certainly Rock Auto

If it upshifts ok while in D, it cant be the solenoids

yes, its ok to use the gearstick

[Browneee]

Thanks for the reply, really appreciate it.

Yep to confirm this morning driving to work when it was cold, it drove normally in D. Up shifted normally and down shifted normally. Only did it on way home from work and only in last say 5klm from home. I’m also going to pull the NSS and clean that out and adjust it. I have noticed my reverse lights playing up.

I called a tranny specialist in Perth today trying to source solenoids locally $350 for 1 and 2 solenoid… he suggested looking at the NSS as he said ‘one good thing JeeP did is put one 0f the most common trannies in the XJ” and the NSS can cause similar problems…


Again this my sound stupid… what’s the web address for the FSM ? I have a Haynes one ? But I’m assuming your talking about a real JeeP one…love to down load it just don’t know where I’m starting to look

Regards Rob