zagscrawler Posted January 17, 2012 Share Posted January 17, 2012 Hello all. my buddy called me today asking me if i could help him with his xj. I know its not an mj but I'm sure it works the same in both. Anyhow here goes... He said he was warming up his truck before he hit the road to go wheeling and when he got in and put it in gear it shifted fine through second and then just reved up like it was slipping after that. He pulled over and shut it down for a few mins and then it worked fine for a bit.. then he hit the freeway and it was in OD when it just started slipping again. He also said it would every once in a while just catch and work ok then would act up with out warning. Any ideas? Any way to check electronics for failures? He did mention that he degreased his engine compartment a few days ago but this is the first time its acted up. Any info would be more then i know. Thanks all :wrench: Oh ya its an 87 4.0l 4x4 Link to comment Share on other sites More sharing options...
kyleag89 Posted January 17, 2012 Share Posted January 17, 2012 Most likely needs a new trans.. Even if it was an electrical problem at one point once it starts slipping its over. I would check the 2 or 3 plugs(can't remember) by the firewall passengers side to make sure they are clean and tight. AW4s can be picked up cheap on craigslist $150-$200 and swapped in a few hours. Link to comment Share on other sites More sharing options...
mvusse Posted January 17, 2012 Share Posted January 17, 2012 Mine only slipped after my alternator went out and the battery got below 9V (two separate occasions now). Still fine. It might be an electrical problem caused by the degreasing, but it sounds more like a problem with the clutches needing a rebuild (or swap). Link to comment Share on other sites More sharing options...
zagscrawler Posted January 17, 2012 Author Share Posted January 17, 2012 Thanks guys ill pass it on. Any one know if he was to hold it in seperate gears manually if it will bypass the electronics enouph to help the diag.? Link to comment Share on other sites More sharing options...
HOrnbrod Posted January 17, 2012 Share Posted January 17, 2012 Thanks guys ill pass it on. Any one know if he was to hold it in seperate gears manually if it will bypass the electronics enouph to help the diag.? Unplug the TCU (or remove the inline fuse powering it) and try shifting manually. Link to comment Share on other sites More sharing options...
Eagle Posted January 17, 2012 Share Posted January 17, 2012 I'm going to guess that the degreasing operation hosed a sensor. I know one of the sensors near the throttle body isn't supposed to get wet. Might be the TPS -- which would affect the transmission. Link to comment Share on other sites More sharing options...
shaylec Posted February 1, 2017 Share Posted February 1, 2017 These Aw4 are pretty amazingly durable. If your Aw4 starts to feel like its slipping, it is most likely the (TPS) throttle position sensor failing. Based on my personal experience. The tps has a potentiometer in it. They wear out. I had this aw4 slipping problem and i hooked up an old snapon diagnostic tool with the jeep module installed and it showed the tps out of tolerance at idle. I reved it up and the tps was erratic. I replaced the tps and all was good again. Link to comment Share on other sites More sharing options...
ParadiseMJ Posted February 1, 2017 Share Posted February 1, 2017 When "de-greasing an engine (especially a 4.0 with an AW4) getting the TPS wet is a no-no. If the symptom started right after the hosing, the TPS is most likely fried. You can test it and or adjust it, but chances are it'll need to be replaced and adjusted. Seek instructions on Cruiser 54's site. And do check the in-line fuse under the passenger knee board. And do check the tranny fluid if it hasn't been done already. The level and the condition IS important. Link to comment Share on other sites More sharing options...
shaylec Posted February 1, 2017 Share Posted February 1, 2017 Thanks for the degreasing warning. That may be very well what killed my throttle tps. I will be more careful next time i spray engine degreaser. Link to comment Share on other sites More sharing options...
Eagle Posted February 2, 2017 Share Posted February 2, 2017 Gotta luv thread necromancy. This thread is only five years old ... And in five years, the OP never came back to tell us if his buddy was able to diagnose and fix the problem. Link to comment Share on other sites More sharing options...
johnj92131 Posted February 2, 2017 Share Posted February 2, 2017 Yes, necromancy! But I have started to notice just a little bit of slip in my AW4 and just now learned about getting the TPS wet. So at least I learned something! Link to comment Share on other sites More sharing options...
HOrnbrod Posted February 2, 2017 Share Posted February 2, 2017 Everybody knows you shouldn't get the TPS wet. :rotfl2: Link to comment Share on other sites More sharing options...
Dzimm Posted February 2, 2017 Share Posted February 2, 2017 Yes, necromancy! But I have started to notice just a little bit of slip in my AW4 and just now learned about getting the TPS wet. So at least I learned something! After reading this thread this morning my aw4 has slipped 3 times today. Never done it before.. And I know my tps didn't get wet... I think this thread is cursed, everyone stay away!! Link to comment Share on other sites More sharing options...
Newton Posted February 2, 2017 Share Posted February 2, 2017 Everybody knows you shouldn't get the TPS wet. :rotfl2: I didn't know that lol..'blocks face' glad I clicked this topic Link to comment Share on other sites More sharing options...
shaylec Posted February 2, 2017 Share Posted February 2, 2017 For those who are innocent, fear not. But for those who harrass me for my admitted ignorance, i will reach into my bag of voodoo juju magic and give you what i like to refer to as "The mj smack down"... at the worst possible time..like when its storming and your on your way to pick up a hot date. Link to comment Share on other sites More sharing options...
cruiser54 Posted February 2, 2017 Share Posted February 2, 2017 Yes, necromancy! But I have started to notice just a little bit of slip in my AW4 and just now learned about getting the TPS wet. So at least I learned something! After reading this thread this morning my aw4 has slipped 3 times today. Never done it before.. And I know my tps didn't get wet... I think this thread is cursed, everyone stay away!! Nobody suggested that guy check the fluid level. LOL. Do this to keep the fluid pressure where it should be. Link to comment Share on other sites More sharing options...
cruiser54 Posted February 2, 2017 Share Posted February 2, 2017 This should also be done http://cruiser54.com/?p=58 Link to comment Share on other sites More sharing options...
Dzimm Posted February 2, 2017 Share Posted February 2, 2017 Yes, necromancy! But I have started to notice just a little bit of slip in my AW4 and just now learned about getting the TPS wet. So at least I learned something!After reading this thread this morning my aw4 has slipped 3 times today. Never done it before.. And I know my tps didn't get wet... I think this thread is cursed, everyone stay away!! Nobody suggested that guy check the fluid level. LOL. Do this to keep the fluid pressure where it should be. Do you think this will help slipping though? Mine has done it 7 times now at 48, 52, and 55 mph Efit: well I adjusted just to see what would happen but it was almost a disaster. The button wouldn't come back up. Luckily after beating on it a little bit it came back up and locked. After work well see if it still slips. Sent from my HTC6525LVW using Tapatalk Link to comment Share on other sites More sharing options...
cruiser54 Posted February 2, 2017 Share Posted February 2, 2017 Check this out: http://www.cherokeeforum.com/f2/transmission-going-221548/index2/#post3203079 Link to comment Share on other sites More sharing options...
Dzimm Posted February 2, 2017 Share Posted February 2, 2017 Well after adjusting the cable it only slipped once on my way home but it also didn't get up to temp until I was almost home. At this point I think I'm going to buy another XJ to be a DD and then pull this trans and replace it. Link to comment Share on other sites More sharing options...
Dzimm Posted February 7, 2017 Share Posted February 7, 2017 Well it continued slipping and seemed to do it more often. I decided to try a fluid change but it still slipped, then tried a spare Throttle position sensor that I had and it hasn't slipped for 2 days even with me trying to get it to slip. I just don't understand how a tps could cause it to slip. It wasn't like the Trans was just disengaging or anything, it was actually slipping. Can anyone explain this to me? Link to comment Share on other sites More sharing options...
shaylec Posted February 7, 2017 Share Posted February 7, 2017 I like to think of it as if your aw4 has a clutch inside that your aw4 or its ecu controls. It won't fully let out the clutch unless it senses that your giving it some throttle... but your tps is telling it that its not giving any throttle even thou your actually flooring it. If you do that with a manual trans you will be slipping the clutch and burning up your clutch plate. If you disconnect the aw4 ecu ( Under dash by passangers feet, it will slip really bad until it seems to figure out that its disconnected and goes into some kind of semi functional loopback mode. Link to comment Share on other sites More sharing options...
Dzimm Posted February 7, 2017 Share Posted February 7, 2017 I like to think of it as if your aw4 has a clutch inside that your aw4 or its ecu controls. It won't fully let out the clutch unless it senses that your giving it some throttle... but your tps is telling it that its not giving any throttle even thou your actually flooring it. If you do that with a manual trans you will be slipping the clutch and burning up your clutch plate. Okay that makes sense. Stupid electronics. I was very worried I'd have to do another trans install. Link to comment Share on other sites More sharing options...
HOrnbrod Posted February 7, 2017 Share Posted February 7, 2017 Lots of misinformation here. 1. First thing to do is make sure your POWER/COMFORT dash switch is in the POWER position. 2. Perform the throttle valve cable adjust as described previously. If you can't adjust it or it's frozen, lube it to get the detent/slider working. If that doesn't work, replace the cable. If this cable isn't adjusted spot-on, it'll feel like the AW4 is slipping. Also crawl under and check out the AW4 TV cable bracket. It sometimes get bent, or the cable end "eye" bushing where it connects to the AW4 pivot arm is broken or missing. These can be replaced. http://comancheclub.com/topic/51298-transmission-not-responding-to-shifter-aw4/?hl=bushing&do=findComment&comment=522543 http://www.bushingfix.com/ 3. Download the AW4 maintenance manual HERE. Perform the Manual Shift Test on page 7. This should get you started in the right direction. Report back after doing these steps.............. Link to comment Share on other sites More sharing options...
Dzimm Posted February 7, 2017 Share Posted February 7, 2017 Lots of misinformation here. 1. First thing to do is make sure your POWER/COMFORT dash switch is in the POWER position. 2. Perform the throttle valve cable as described previously. If you can't adjust it or it's frozen, lube it to get the detent/slider working. If that doesn't work, replace the cable. If this cable isn't adjusted spot-on, it'll feel like the AW4 is slipping. Also crawl under and check out the AW4 TV cable bracket. It sometimes get bent, or the cable end "eye" bushing where it connects to the AW4 pivot arm is broken or missing. These can be replaced. http://comancheclub.com/topic/51298-transmission-not-responding-to-shifter-aw4/?hl=bushing&do=findComment&comment=522543 http://www.bushingfix.com/ 3. Download the AW4 maintenance manual HERE. Perform the Manual Shift Test on page 7. This should get you stated in the right direction. Report back after doing these steps.............. I don't have a power/comfort switch. This is actually in a 98 XJ SE so no fancy stuff. I will have to lube the cable button yet to see if it moves freely again but I was able to adjust it when I tried. I also did inspect the linkage and cables while I was under it changing the fluid and everything looked fine. Thanks for the links they are helpful. I did end up finding the aw4 manual and it has a lot of useful info. Like I said it's no longer slipping at least hasn't for 3 days. I can't even get it to slip while trying so it seems to me the tps fixed it. Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now