Eagle Posted February 16, 2021 Share Posted February 16, 2021 On 2/14/2021 at 4:52 PM, driveslowsnackoften said: Update from work yesterday. Dumped just under 3 quarts of ATF that smelled of burnt roadkill and replaced with 4qt. Not having enough to do another complete dump figured it would be good to drive into town to recirculate, get more, flush again. I took the hill route, so if it were to slip, it would leaving the house instead of getting stuck coming home. Seemed to handle it no problem, as with the next couple small hills. But on the return trip it noticeably slipped, with the engine revving up twice, then complete lack of power on the same hills on the prior trip. So you haven't done the second drain and refill? I wouldn't do anything else until you have done that. As I posted above, the torque converter holds a significant amount of joy juice, so just draining the pan (even if you drop the pan) doesn't get all the old, burned fluid out. I think you need to do at least one more drain and refill cycle, maybe two more. If that doesn't solve the problem, then you can start looking for other issues. Link to comment Share on other sites More sharing options...
zomeizter Posted February 17, 2021 Share Posted February 17, 2021 OP, transmission slippage is usually due to worn/damaged components. Every once in a while, one gets lucky and a fluid flush and filter replacement improves functionality but the damage is there. Sometimes a band adjustment does the trick too. If you were to take it to a tranny shop for diagnosis I can guarantee you that they'll tell you your tranny is shot and needs a rebuild, no matter what the issue is. Now, the way you describe the symptom points to a temperature correlation, if the unit is electronically controlled, you may have a "weak" solenoid or any piece of the circuitry or something is expanding with the heat causing malfunction. There are experts out there that will pinpoint the problem and explain this to you, then you can make a decision on how to resolve the issue, but these honest dudes are hard to find. If I was in your shoes, I'd start looking for a replacement slush box, good units are out there, shop around...or just have it rebuilt with upgrades inclusion, good luck man. Link to comment Share on other sites More sharing options...
driveslowsnackoften Posted February 18, 2021 Author Share Posted February 18, 2021 Welp, I've done a second flush and need to run into town so I'll see how it goes. If it does slip again I'll proceed with testing the TCU. Link to comment Share on other sites More sharing options...
Pete M Posted February 19, 2021 Share Posted February 19, 2021 keep us posted! Link to comment Share on other sites More sharing options...
driveslowsnackoften Posted February 19, 2021 Author Share Posted February 19, 2021 So it looks like the second flush has made a huge improvement. I made a near repeat of the last trip (~15mi ~2000ft total gain) without a definitive slip. There were a couple places where I felt like it should have shifted but didn't and maybe feeling like this was improving? that might be just being hopeful though. And being that I am feeling hopeful, I am going to flush a third time before trying to push a further trip. Link to comment Share on other sites More sharing options...
Pete M Posted February 19, 2021 Share Posted February 19, 2021 sounds promising! Link to comment Share on other sites More sharing options...
Minuit Posted February 19, 2021 Share Posted February 19, 2021 You'll have to do this another time or two to fully cycle out the old fluid. I'd definitely suggest a filter change if the transmission seems like it'll live. Link to comment Share on other sites More sharing options...
driveslowsnackoften Posted February 19, 2021 Author Share Posted February 19, 2021 Yeah good call, I've got the filter and gasket already so should just go ahead with it. Also, just to say aloud, I have a JeepCables replacement kit I keep procrastinating installing. Link to comment Share on other sites More sharing options...
CGCWO Posted February 21, 2021 Share Posted February 21, 2021 Thanks for posting this, besides my idle problem and some slight backfiring I am having a similar problem. Lose power going forward after a few minutes. Going to try the drain/fill/drain/fill and so on after I change out the messed up trans cooler lines next week. Fingers crossed your problem is fixed and mine can be. Link to comment Share on other sites More sharing options...
AZJeff Posted February 21, 2021 Share Posted February 21, 2021 The AW-4 is an unusually durable transmission. The only way to kill one is to seriously overheat it and cook the clutches. Occasionally, the solenoids act up, but other posters have given tips on how to diagnose that. Of course, any overheating does damage to the fluid, so anytime there is suspicion of heat damage to the fluid (smell/color evidence), a thorough flush of the system is warranted. Doing it by the drain/fill/drive cycle several times is the cheapest way, especially since the AW-4 has a drain plug. On the last drain/refill, change the filter and clean the pan, and call it a day. Link to comment Share on other sites More sharing options...
driveslowsnackoften Posted March 19, 2021 Author Share Posted March 19, 2021 Figure I should put an update on this one. I still haven't pulled the pan and done the filter as I wanted to be semi-confident it was worth the effort. But after the third flush, I've made several ~20 mile trips into town and back with definitive slipping, though on the last trip I heard some whining that sounded like power steering(*) but was very much in sync with the gas pedal. It was pretty cold out and only made it on the first half of the trip and otherwise felt fine. So with that, next step is to drop the pan and do the filter. I also found another AW4 for cheap, so I'm thinking of getting it as a back/future bench rebuild. *) Power steering was also having issues during this saga but the pressure line has been replaced and it's holding fluid now. Link to comment Share on other sites More sharing options...
cruiser54 Posted March 20, 2021 Share Posted March 20, 2021 adjust your throttle valve cable. What's the fluid look like now? Link to comment Share on other sites More sharing options...
driveslowsnackoften Posted March 20, 2021 Author Share Posted March 20, 2021 I'm going to get out there for some work in an hour and will have a look at this. What's the idea here, that fluid isn't actually being fully circulated? Link to comment Share on other sites More sharing options...
AZJeff Posted March 20, 2021 Share Posted March 20, 2021 2 hours ago, driveslowsnackoften said: I'm going to get out there for some work in an hour and will have a look at this. What's the idea here, that fluid isn't actually being fully circulated? No, the trans throttle cable controls some of the fluid porting in the trans. When mine was out of adjustment, the trans would slip in and out of gear randomly at cruising speed, yet would accelerate fine. Link to comment Share on other sites More sharing options...
driveslowsnackoften Posted March 20, 2021 Author Share Posted March 20, 2021 ok I see. I'll have a look and probably worth noting it feels like the shifting is fine, but if anything, maybe doesn't shift back to a lower gear as early as it should. We've been putting off a long drive (and missing out on quality adventure) for long enough.... this afternoon we're heading out for a bit under 400 miles weekender. Wish us luck! Link to comment Share on other sites More sharing options...
cruiser54 Posted March 20, 2021 Share Posted March 20, 2021 adjust the cable ASAP Link to comment Share on other sites More sharing options...
Dzimm Posted March 20, 2021 Share Posted March 20, 2021 Have you unplugged the TCU and tried to drive it yet? Much cheaper than throwing fluid at it and will actually tell you something. Troubleshooting is free, the parts cannon gets very expensive and time consuming. Link to comment Share on other sites More sharing options...
cruiser54 Posted March 20, 2021 Share Posted March 20, 2021 TV cable takes 22 seconds to do. Link to comment Share on other sites More sharing options...
driveslowsnackoften Posted March 20, 2021 Author Share Posted March 20, 2021 WIll be done before the drive but as it just started hailing.... it'll be a minute... Link to comment Share on other sites More sharing options...
driveslowsnackoften Posted March 20, 2021 Author Share Posted March 20, 2021 Hail yeah Jeep! Before it started I was looking at the TVC and the plunger(?) was full in. Stopped so going to adjust it now. Link to comment Share on other sites More sharing options...
driveslowsnackoften Posted March 20, 2021 Author Share Posted March 20, 2021 Hmmm, so with it all the way in, this procedure doesn't seem to do much if anything. Completely flooring it moved MAYBE an 1/8th " but I wouldn't be shocked if it didn't actually move. Link to comment Share on other sites More sharing options...
cruiser54 Posted March 20, 2021 Share Posted March 20, 2021 Push the button in and PULL the cable housing toward the valve cover. Link to comment Share on other sites More sharing options...
driveslowsnackoften Posted March 20, 2021 Author Share Posted March 20, 2021 Yup, that's what I did. I've done it again and verified it is moving 1/16th Link to comment Share on other sites More sharing options...
cruiser54 Posted March 20, 2021 Share Posted March 20, 2021 Okay. How does the fluid look now? Does your Power/Comfort switch light up when switched to Power? Is the "trans" fuse in the fusebox good? Link to comment Share on other sites More sharing options...
driveslowsnackoften Posted March 22, 2021 Author Share Posted March 22, 2021 Welp, that didn't go great. We made it 14 miles /w 2000ft before it started slipping again... On 3/20/2021 at 4:29 PM, cruiser54 said: How does the fluid look now? The fluid looked fine but had a hint of burnt smell like it had before. On 3/20/2021 at 4:29 PM, cruiser54 said: Does your Power/Comfort switch light up when switched to Power? Is the "trans" fuse in the fusebox good? The switch is broken and the light is always on. I'll check the fuse later today. On 3/20/2021 at 2:04 PM, Dzimm said: Have you unplugged the TCU and tried to drive it yet? I used the opportunity to thoroughly test this and for a minute thought it was going to be the solution but climbing back up to the house it eventually started slipped again. It really feels like the transmission is badly overheating. Could the original low fluid overheating event clogged or otherwise damaged the cooler line? Link to comment Share on other sites More sharing options...
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