AW4, 4x4, 4.0L, '98 XJ Slow to get goin'

[halmca]

"Late model" trans with input shaft speed sensor, with about 100k on the trans.

Get in the Jeep crank 'er up, put 'er in first or reverse, as appropriate, and I gotta bring 'er up to about 3500rpm to get it to shove off.

Almost immediately after we get goin', it shifts normally through all the gears, including torque converter lock up. Up, down, and all around.

Go into the store, buy some whiskey or get a covid vaccine, or both, come back out and it shifts fine, no noticeable hesitation.

A few hours later sittin in the garage, gotta goose it to go again, but not so much as if it had been setting overnight. But still gotta goose it.

CEL (MIL) light is on. It will clear with scanner, but soon comes back on. "P0700 generic Current Transmission Control System (MIL request)"

So whassup?



T

 

[Agreen]

I don't want to insult your intelligence, but I gotta get the basics out of the way. How's the fluid level look?

 

[Jelliott78]

My 98 felt sluggish when starting from a stop. I found a bad solenoid for 1st gear. It was starting in second. How does it do when you put it in manual 1st?


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[lawsoncl]

If it's doing it in reverse, it's not solenoids. Sounds like a bad check valve and the t/c is draingin back into the pan?

 

[halmca]

I don't want to insult your intelligence, but I gotta get the basics out of the way. How's the fluid level look?

It looks good. Not insulted.

 

[halmca]

Yup. Doing it in reverse. Is the check valve located in the trans or in the T/C? Aside from a bit of inconvenience, is there any harm in driving it this way for a month or so?

 

[Agreen]

Fortunately it does sound like it's a problem in the valve body and not the clutches/bands of the transmission. It's kind of a gamble, but I'd spend the $80 on a Transgo HD-2 kit and check the valve body over while it's out.

 

[RCP Phx]

Fortunately it does sound like it's a problem in the valve body and not the clutches/bands of the transmission. It's kind of a gamble, but I'd spend the $80 on a Transgo HD-2 kit and check the valve body over while it's out.

If you do, don't waste your time on the cheaper kit.

 

[halmca]

If you do, don't waste your time on the cheaper kit.

Assuming that the $80 kit is not the cheap one . . . or is it. There's a pretty cool video showing the installation of one of these kits at the following url. The actual installation begins about 13:00 in on the video.

So you two guys -- the two who address this kit -- apparently believe that my issue is presented by the valve body. It is very tempting to get one of these kits and give it a shot, for two reasons: 1) I'd like to get the AW4 to shift a bit more crispy when it does shift. and 2) while the issue may be other than valve body failure, it is (in my town) about $2100 cheaper than a rebuild of the AW4. So seems to me it's worth the gamble cuz even if it doesn't cure my issue, it will still yield better shifts if/when I fix the issue with which Im now dealing.

Please let me know your thoughts.

Here's the video: https://youtu.be/UAwXrRi4FJM

 

[Agreen]

I think the cheaper kit he's referring to is the SK 340, which is a "shift restoration kit". The 340-HD2 kit is the "reprogramming kit" which will give you the firmer, crispier shifts. I installed one shortly after I converted my 2wd to 4wd and I loved it. I can't guarantee that it'll fix your problem, but it does sound likely that your issue is in the valve body.

Right out the gate, I'd swap the shift solenoids with the one you have sitting in your garage. You're not spending any extra money on it, and should you be successful you could then move towards the shift kit. Valve body work can be kind of daunting, but if you take your time, watch for falling bb's, and follow the instructions, you should be just fine.

Also, I did the "truck" setting. I haven't tried it, but the "race car" setting will supposedly slam every gear.

 

[Agreen]

I just watched the video. I wish that existed when I did mine. I have to admit, I'm kind of afraid of automatic transmissions. Yes, I tore mine down and rebuilt it to make it 4wd, but it was the first I'd ever done and I was a little apprehensive. But the HD2 kit was really straightforward and has great instructions. I did have to wait a few days for a new gasket because mine ripped, but those guys are saying it's not necessary. I don't know how much I trust that, but maybe they're right?

One more bit of info about the HD2 kit: The 1st gear hold feature is awesome. And the transmission is smart enough to NOT shift to 1st if you accidentally bump it to the 1-2 position. It will downshift to 2nd, then around 25 mph it'll hit 1st. It won't come out of 1st though, unless you select 3 or D. But for off-road purposes, it's an excellent feature and I did like it when mine was still auto (I just converted mine to manual)

 

[halmca]

Geeze, do I ever wish you were my nearby neighbor. I too am converting 2WD to 4x4 and what a journey it has been so far! I'm gonna order the more advanced kit this morning. Thanks for the reccomendation.

The whole idea behind getting my XJ was to keep my retired butt busy and out of the feedbag during this pandemic. Its effectiveness insofar as both of those purposes are concerned has exceeded all expectations! :doh:

 

[Agreen]

Yeah I'm nowhere near retired and mine keeps me busy for sure. Not because it breaks down or has problems, but because I can't stop fooling with it.

Funny. My neighbors wish they weren't my neighbors because they have to listen to my impact running all day

 

[75SV1]

I'd unplug the trans controller, or the fuse for it. Shift manually. If OK, then its something electronic. I'd check the level as you have. I'd change the fluid a few times. Dextron II. Another is the two speed sensors. There is a front and rear on the 98+ Trans. I went through something similar. I did put in the lower grade trans kit. It did not help me. I also, put in new solenoids. Didn't help me. I also had a new NSS (Range Selector), before this was an issue. It happened to be the rear speed sensor. That was not a fun experience. The bolt broke in the case. There is a test for these speed sensors. Use an analog volt/ohm tester though.

 

[RCP Phx]

Geeze, do I ever wish you were my nearby neighbor. I too am converting 2WD to 4x4 and what a journey it has been so far! I'm gonna order the more advanced kit this morning. Thanks for the reccomendation.

The whole idea behind getting my XJ was to keep my retired butt busy and out of the feedbag during this pandemic. Its effectiveness insofar as both of those purposes are concerned has exceeded all expectations! :doh:

You need to know that the shift kit allows more features than a manual shifter, like adjusting the line pressure for firmer shifts.

 

[halmca]

EVERYBODY READY FOR A GOOD LAUGH?????

Transmission shop says it was 3.5 quarts LOW ON FLUID. AW4 now shifts like a new one. They didn't change me for the fluid -- out of kindness, I suppose.

Now, checking transmission fluid ain't exactly the stuff or rocket science. I not only checked it several times, I drained a quart tried to drive it, and then filled it up to the mark and added a quart to that. And Yeah -- I ran the Jeep around the block a time or two, engine up to temp, transmission in neutral and engine running.

Sadly, I appear to be the weak link in the causal chain. Many thanks to those of you who at least tried to help.

I'm not feeling too bright. Gonna distribute a few quarts of Jack Daniels at the shop tomorrow.

 

[Agreen]

Well, that'll do it!

Time to close this chapter of your transmission woes and move on to something else. Maybe a lift kit or a winch bumper is in your future?

 

[halmca]

Well, that'll do it!

Time to close this chapter of your transmission woes and move on to something else. Maybe a lift kit or a winch bumper is in your future?

LOL: chucking the 2WD front axle and installing the 4x4 differential, etc, should provide some entertainment as well as opportunity to kiss off several hundred dollars. Stand down, but stand by.

 

[75SV1]

Did you check with the vehicle running and in neutral? Also, level?

 

[halmca]

Did you check with the vehicle running and in neutral? Also, level?

I did. And not just once, but several times as did my helper, an ASE certified young guy. LOL: the one thing I can't doubt is that with the addition of nearly a gallon of ATF, it works jes' fine! Facts is facts, and some of 'em are hard to understand.