89eliminator Posted April 11, 2008 Share Posted April 11, 2008 well, my aw-4 isnt going into overdrive. i'll try to explain it the best i can It shifts fine from 1-3. It does go into overdrive, but its revving higher than before. If you leave it in "3" it will shift the three gears and stay in 3rd which is obviously normal. well if i shift into "OD" it will drop rpm's but only about 200. before i parked it over the winter, it would run around 1900 rpms at 60, with my 33s and 4.10 gears. now its up to 2300 at 60. I'm thinking its the torque converter not locking all the way. anyone else ever exprience this or have an answer. Link to comment Share on other sites More sharing options...
beaterjeep Posted April 11, 2008 Share Posted April 11, 2008 Time for another MJ. :D Sorry, I can't be of much tech help, I'm here for entertainment values. OH, could it possibly be like the TPS? or are they of no issue to this? Link to comment Share on other sites More sharing options...
juan Posted April 11, 2008 Share Posted April 11, 2008 I had a similar problem mith my 97xj - I know your mj is older but we both use the same transmission. My problem got solved when I removed the NSS and clean it, also make sure your NSS is installed and adjusted propertly. good luck. Link to comment Share on other sites More sharing options...
CWLONGSHOT Posted April 12, 2008 Share Posted April 12, 2008 I had a similar problem with my 97xj - I know your MJ is older but we both use the same transmission. My problem got solved when I removed the NSS and clean it, also make sure your NSS is installed and adjusted properly. good luck. Juan knows this... he just went thru it a couple months back!! This is my suggestion as well. In-case you didn't know, the AW4 is computer controlled so if the switch is dirty or faulty, this could very well be your problem!! Link to comment Share on other sites More sharing options...
89eliminator Posted April 12, 2008 Author Share Posted April 12, 2008 thanks, i'll check it out tommorow Link to comment Share on other sites More sharing options...
Andy in Pa Posted April 12, 2008 Share Posted April 12, 2008 You may know this test already, but a good way to check if the Jeep is going into overdrive or not is to get to a steady speed above 40 mph. Then, with one foot on the gas to maintain speed, lightly depress the brake pedal. You will see the rpms jump as it comes out of overdrive. Then the rpms will go back down when you take your foot off the brake and it shifts back into overdrive. This is my ultimate test to see if overdrive is working. A. Link to comment Share on other sites More sharing options...
89eliminator Posted April 12, 2008 Author Share Posted April 12, 2008 You may know this test already, but a good way to check if the Jeep is going into overdrive or not is to get to a steady speed above 40 mph. Then, with one foot on the gas to maintain speed, lightly depress the brake pedal. You will see the rpms jump as it comes out of overdrive. Then the rpms will go back down when you take your foot off the brake and it shifts back into overdrive. This is my ultimate test to see if overdrive is working. A. see, it does do that, but its not dropping enough rpms. it only drops about 200 rpms and is revving too high. Link to comment Share on other sites More sharing options...
mvusse Posted April 12, 2008 Share Posted April 12, 2008 Maybe the torque converter is fine, but the clutches are slipping? Link to comment Share on other sites More sharing options...
james750 Posted April 12, 2008 Share Posted April 12, 2008 TCU? Link to comment Share on other sites More sharing options...
89eliminator Posted April 12, 2008 Author Share Posted April 12, 2008 Maybe the torque converter is fine, but the clutches are slipping? I'm thinking its something that is dirty, like the nss. i've had the truck parked in storage since november and it worked fine before that. The DAY i brought it out, it didnt work... Link to comment Share on other sites More sharing options...
mvusse Posted April 12, 2008 Share Posted April 12, 2008 Could it be electrical? Maybe some vermin have been chewing on the cables... Link to comment Share on other sites More sharing options...
89eliminator Posted April 12, 2008 Author Share Posted April 12, 2008 Could it be electrical? Maybe some vermin have been chewing on the cables... well it was in a heated garage all winter, that i was in everyday and didnt see any rats or anything. i'll check out the electrical stuff though Link to comment Share on other sites More sharing options...
JeepcoMJ Posted April 12, 2008 Share Posted April 12, 2008 tcu or something in the throttle body like the tps or the cable from throttle to trans Link to comment Share on other sites More sharing options...
HOrnbrod Posted April 12, 2008 Share Posted April 12, 2008 I'm thinking its something that is dirty, like the nss. i've had the truck parked in storage since november and it worked fine before that. The DAY i brought it out, it didnt work... AFAIK, the NSS has nothing to do with shifting the AW4. It's purpose in life is to prevent you from starting in any other gear besides N or P, provide a circuit for the backup lights, and provide a continuity ground to the ECU to allow starting. Once started, the NSS is out of the TCU circuits and tranny solenoids that control shifting. You can pull the NSS and clean it, can't hurt, but first, since it's been sitting for awhile, I would drain the tranny, change the filter, and add about four quarts of fresh ATF. Especially if it's not been done in awhile. Link to comment Share on other sites More sharing options...
89eliminator Posted April 12, 2008 Author Share Posted April 12, 2008 I'm thinking its something that is dirty, like the nss. i've had the truck parked in storage since november and it worked fine before that. The DAY i brought it out, it didnt work... AFAIK, the NSS has nothing to do with shifting the AW4. It's purpose in life is to prevent you from starting in any other gear besides N or P, provide a circuit for the backup lights, and provide a continuity ground to the ECU to allow starting. Once started, the NSS is out of the TCU circuits and tranny solenoids that control shifting. You can pull the NSS and clean it, can't hurt, but first, since it's been sitting for awhile, I would drain the tranny, change the filter, and add about four quarts of fresh ATF. Especially if it's not been done in awhile. i changed it last summer Link to comment Share on other sites More sharing options...
89eliminator Posted April 12, 2008 Author Share Posted April 12, 2008 tcu or something in the throttle body like the tps or the cable from throttle to trans tps was good, i checked it. and i don't think it would be the cable, because it shifts prefect besides overdrive. Link to comment Share on other sites More sharing options...
deziped Posted April 12, 2008 Share Posted April 12, 2008 Use a circuit tester and measure Converter Clutch Solenoid Resistance. With key OFF and TCU unplugged using the connector side place negative lead in D7 and postive lead in C 14 (Wht/blk) read the Ohms. A good solenoid will read 11-15 ohms. Any less & it has problems. You can also ckeck the trans Range Sensor Connector at left rear of block (Violet - no stripe wire) near heater control valve area to see if it has elec flow. Link to comment Share on other sites More sharing options...
89eliminator Posted April 14, 2008 Author Share Posted April 14, 2008 i found the problem. it was the brake switch. It was out of adjustment. It rests against the brake pedal, and when you depress the pedal it releases telling the torque convertor to stop. Link to comment Share on other sites More sharing options...
Twisty Posted April 14, 2008 Share Posted April 14, 2008 Nice detective work! 8) Link to comment Share on other sites More sharing options...
HOrnbrod Posted April 14, 2008 Share Posted April 14, 2008 i found the problem. it was the brake switch. It was out of adjustment. It rests against the brake pedal, and when you depress the pedal it releases telling the torque convertor to stop. I thought the 1990 and below brake switches were non-adjustable? I know they are not interchangible with the adjustable 91+ switches. Link to comment Share on other sites More sharing options...
89eliminator Posted April 14, 2008 Author Share Posted April 14, 2008 i found the problem. it was the brake switch. It was out of adjustment. It rests against the brake pedal, and when you depress the pedal it releases telling the torque convertor to stop. I thought the 1990 and below brake switches were non-adjustable? I know they are not interchangible with the adjustable 91+ switches. i dunno. all i know is that mine adjusted. Link to comment Share on other sites More sharing options...
HOrnbrod Posted April 14, 2008 Share Posted April 14, 2008 i found the problem. it was the brake switch. It was out of adjustment. It rests against the brake pedal, and when you depress the pedal it releases telling the torque convertor to stop. I thought the 1990 and below brake switches were non-adjustable? I know they are not interchangible with the adjustable 91+ switches. i dunno. all i know is that mine adjusted. Interesting. How many wires were on the switch connector? Reason I ask is because I was helping a friend via email who had an 89 who was doing the 95/96 booster/master upgrade, and he ended up having to change out the brake switch and bracket for a 91 adjustable switch. Link to comment Share on other sites More sharing options...
89eliminator Posted April 14, 2008 Author Share Posted April 14, 2008 2, blue w/ yellow tracer, and a black wire. Link to comment Share on other sites More sharing options...
HOrnbrod Posted April 14, 2008 Share Posted April 14, 2008 There are six wires on the 91+ switch. Two for the stop lights (NO), two to the TCU for the torque converter and the ECU (NC), and another pair for the cruise speed sensor (NC). Entirely different. Well, I'll contact my friend w. the 89 and ask why he could not adjust his brake switch as you have done Wade. :cheers: Link to comment Share on other sites More sharing options...
ComancheKid45 Posted February 18, 2012 Share Posted February 18, 2012 WOW I know this is an OLD topic but I'm having the same issue... I just did the 96+ booster/MC upgrade and had to mod the arm just a bit for the brake light switch to bolt up, and now my trans will not go completly into overdrive... What excatly was your fix for this Wade (if you remember)? Did i not grind off enough of the new arm for the switch to rest on or could it simply be a loose connection? Thanks for any help! ;) Link to comment Share on other sites More sharing options...
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