I have a 99 XJ 4.0 with a AW4 with 212000 miles. Ive owned it for 3 years. Ive been having a intermittent issue that is starting to become more frequent, but still intermittent. After I start the Jeep (it always starts and idles normal) but once I shift into drive and hit the accelerator pedal to go forward sometimes it feels like there is a load on the engine pulling it down. Its very hard to describe but its like it struggles to reach 2nd. Once it gets to 2nd it shifts fine. During the rest of the drive cycle 1st to 2nd shifts are normal from stops. I also notice when it does this and say I am pulling out of my parking space but go stop at the end of the aisle for other traffic when its doing this it will pull the engine down below idle like down to 250rpm almost like it wants to stall out. If it shift into nuetral when I have to stop and the load is pulling the engine down it allows the engine to get back to idle and when I shift back to drive it drives normal. And lately I just started to notice when I shift to nuetral to let the load off the engine, its not immediate the engine gets back up to idle. This is making me think less that its the transmission.

Again it is very intermittent. There are many times I start the Jeep shift into drive and it drives away normal. It doesnt matter if the fluid is cold or warmed up. But it only happens after statup when it does do this.

The transmission fluid level is always good. Ive been doing periodic drain fills with Valvoline ATF4 over the years Ive owned it. I do need to just bite the bullet and put a new filter in the transmission. I have a Wix filter in the garage. Ive just been dreading it because I dont want mess with disconnecting the lines going into the pan.

I was thinking too the issue could be related to the shift solenoids but I figured Id ask here first to see if any of you experienced the same before I just start throwing more parts at it.

Thanks for reading this long post if you made it this far! I just figured the more descriptive I am maybe someone can help me diagnose it more easily. Pic of my XJ for fun too!

Thanks!

 

you dont need to remove the disconnects, as they dont go into the pan

however I doubt it will be the filter, as it is just a wire mesh

If you have a bad solenoid, it will give specific shift problems outlined in the FSM, and will not normally be intermittent

 

It was the dipstick tube Im thinking of. Yeah thats kindof why Im in no rush to change the filter because its more or less just a rock catcher.

 

• You do not need to change the "filter". It's not really a filter on this transmission. It's wire mesh screen. If you ever see any debris caught in one of them, it's because the trans is coming apart and losing big chunks. The filter is the least of your worries at that point.
• Why are you using the wrong transmission fluid? The only thing recommended by the manufacturer (Asin Warner) is Dexron III / Mercon, commonly referred to as Dex/Merc. That may be your entire problem. More likely, you have accelerated the wear on your trans by using the wrong fluid.
• It's not hard to change a solenoid, but check all your grounds, first. It's possible it's an electrical problem, and it never hurts to clean up your grounds anyway. It's not a high probablity, but doing it is pretty close to free, so you might as well. See my sig, #1.

 

Thanks for pointing that out! I mentioned the wrong fluid. My TJ uses ATF4. Ive been putting in Valvoline Max Life Dex/Merc ATF in my XJ.

I did end up pulling the pan off today. I checked the resistance of the solenoids and they all read 13.2ohms. The FSM says the range for the solenoids should be between 11-15ohms. So like you guys already mentioned, its doubtful the solenoids are bad.

While I was in there I did swap out the filter (screen) since I had it already. Good news is I saw no huge metal chunks. Just the normal metal muddy dust stuck to the magnets. I cleaned up the pan and magnets and put 4 fresh quarts of the Valvoline Dex/Merc ATF in it.

I hope this is not a sign my AW4 is getting tired. I just need it to stay as it is for another year.

 

The good thing is that with even "minimal" mtc, the AW4 lasts almost forever. You have obviously done more than minimal mtc so i assume your fluid is still red-ish. My old 92 had over 350k on the tranny with less mtc than yours and my 01 has over 250k ...so my point is that while you may have a specific fixable issue...its probably not tired or worn out. Thats a fantastic looking 99.. The idle air valve should not let your idle drop much below 625. Have you taken it apart and cleaned the cone on the valve and the receiver in the throttle body. You can do it with the TB still bolted to the intake.

 

Ive done several drain fills in the past 3 years to get most of the old fluid out. It was pretty dark but now its red with some tint in it. Yeah I hope it stays like this. Its been doing this intermittent thing since ive owned it. I did clean the IAC valve when I put a new exhaust mainfold and had the intake manifold off. I also cleaned out the intake manifold. Thank You on the compliment. I spent a lot time fixing this up. It's nearly perfect minus this transmission issue and the rockers are just starting to bubble .

 

the lifespan of the AW4 is not indefinite, and hot weather seems to be a big factor,

I have had it confirmed by auto trans specialists, and my own observations, that they often fail not long after 200k miles

It is hot here, so it depends a bit on the ambient temp and use over its lifespan

looking any chart regarding Auto trans life vs Fluid Temp

What State does that excellent looking White XJ spend its time in ?

 

I live in Indiana. And it spent most of its life in Kentucky. I picked it up about 5mins near the Jim Beam Distillery

 

You have done the right thing, and it probably won't help at this point, but see my sig, #3. Can't hurt.

 

The past couple of months my 01 started to develop a slight miss at idle, and on cold days it would intermittently become hard starting, where normally it fired right off as soon as I hit the key. Did all the usual stuff thinking it was ignition related. I have it stroked and am running a coil rail eliminator. Tried playing with the wires and adjusting my cam timing sensor. All no help and mostly intermittent.Would get a misfire code when it wouldn't start. For the hell of it I changed out my Crank Position Sensor. The miss is gone and it fires up every morning for 3 weeks now with 0 issues. The old one was orig and had 255K on it. It looked ok but had a small pencil eraser sized pile of magnetic fuzz on the tip but the new one seemed to clear up those issues. I got it at Advance with a limited lifetime warranty for 35 or 40 bucks after their coupon codes and some speedperks. An hour or so in the street...might be easier in your nice clean garage.. Couldn't hurt for 40 bucks and an hour...you could always reinstall the old one if not satisfied. My bolts were 11mm. I only mention this because its not really tranny related but you say how it still sometimes has a low idle even after you shift into N

 

Paragraph lives matter.

 

Not a bad idea. I always hear the CPS is a common problem and leads to lots of wierd things. Thanks!

 

The CPS is not going to cause an transmission problem.

 

I like the link!!!