Something is likely wrong with your transmission/torque converter if it is not locking up in low gears. It could also be the trans controller that's in the cab is faulty (maybe try this first). My 1990 has just a basic parts store cooler after the one built in the radiator cooling it, 33's but on 3.73 gears, 4.7 stroker but it never gets above 220 in the California heat. I don't go easy on the throttle, I roll 85+ all the time on the highway, when I'm off road it gets the same punishment. If you can't keep the temps down, put the cooler in front of the radiator like everyone else does, they don't restrict air flow that bad.
100% I believe my TC is damaged and causing too much slippage. I could be wrong, but I don’t think the AW4 TC has lockup capabilities in 1st & 2nd gear from everything I have read. My tc locks up just fine but only in 3rd & 4th gear. Keep in mind most Jeepspeed 4.0’s on 35’s need to run a $800 Trans cooler that looks like a mini radiator and they still run at 250f in a sand wash. It seems the AW4 just runs hot. Nevertheless, I am certain that if I rebuilt my tranny and put a new tc in, it would make a huge difference.
@@fabguy276 It might not have it in 1st, but it definately has it in 2nd and up, I think it might only lock up in 2nd if you have the shifter locked in 2nd
I've got one tranny cooler on my 96 but it's not as modified as yours is the only thing that I've done minor stuff to it I've got stock gears so I'm only running 30s and it's two-wheel drive so I don't have a pumpkin up front 3-inch lift it's definitely a lot lighter than yours so maybe I'm not putting a lot of strain on the tranny but I've separated the fluids radiator worries about the engine and the cooler is for the tranny I know that the aw4 is super tough but I still havent looked at temps I need to get a gauge I live in Redlands so it doesn't get as hot up the hill where your at I know yucca still gets hot
Hey FabGuy, have you tried upping the trans fluid viscosity to better match rotational speeds in torque converter and lock up easier ? Something like Lucas trans Stop Slip. Meant to help with temps too.
Have you changed the torque converter or is it original? I beat on a cherokee with 33s and stock gearing for years and eventually the torque converter blew up like literally blew up. I know youve mentioned having 4.10s or 4.56s i forget so it should be close to stock with your 35s and not too hard on it. One thing i was thinking is your converter could be slipping more than its supposed to they do wear out. When my converter blew i overhauled my whole transmission but everytime i have a high milaege xj apart i put a new converter in it. You may be dealing with a worn out converter thats slipping too much but is still able to lock. What i look for in that instance is lots of heat and if the fluid is getting dirty or kinda burnt smelling. It might be worth it to replace the torque converter. I was thinking maybe your lockup solenoid was malfunctioning but it sounds like it locks up no problem. If you were to ever replace a solenoid do not run aftermarket ones you want new oem asin ones or used ones they are easy enough to bench test. I think you should keep working on the xj everyone has a jk heavily modified and dialed in xjs are really cool but you have to work hard for it sometimes. Its kinda tough for me to judge your heat issue because of your sand driving and stuff but i compare it to when i used to drive my cherokee years ago with 33s and stock gearing i had heavy bumpers and armor and a spare tire on the roof etc.. plus i would haul a trailer with 2 dirtbikes and i just had 1 tranny cooler or 2 smaller ones for a little while and i very rarely saw over 180 on the trans temp and that was on the road going over the mountain pass with dirtbikes in tow trying to go 60 mph. Then theres been lots of other instances over the years where i really ran it very hard i daily drove it for like 6 years or so with stock gears and 33s in that form until the converter let go. Mine never made heat it just blew apart. Im also running royal purple max atf i think thats one of the best fluids for the aw4. If you ever have it apart for something I'd change the torque converter for sure and inspect the flex plate for cracks. If your up for it you may want to take it apart specifically to replace the torque converter and give it a try. There are some high end converter companies that have one for an aw4 i remember looking and i found a website that sorta specialized in aw4 stuff also the a340 in the supra is the same transmission essentially. Its worth it spending the extra money on a high quality converter. Also if you do take it apart to do the converter thats a good time to replace the original freeze plug in the back of the block behind the flexplate and block plate with a brass one if its original its a pain when those rust through if you have rust in your system. You may not have any issues so it might not be worth it to tear into it unless you can really pin point it. But it kinda sounds like its slipping too much and creating more heat. I know in diesel trucks ive experienced bad torque converters in the same way they seem to work just fine but build up lots of heat and you can really tell when you try to spool it up and get on torque theres just nothing much there it doesn't get up and go like it should it will go pretty good but not like it should ive dealt with that a few times. Ive actually replaced quite a few torque converters over the years and theres been a few that have been difficult to diagnose because the performance didn't seem to be down that much but once it was replaced you could definitely tell. This is a long comment lol but anyways it seems to be coming along nicely i like the roof rack.
Thanks for the time and insight. I’m going to agree with you and say it’s the converter for sure. My dad told me the same thing. I guess that is my next project….
@@fabguy276 if the converter comes painted it may be a good idea to brake clean off the paint my last one was painted blue and it was stinky as it burned off which is normal for things like freshly painted engines and parts and such but for whatever reason it took like 3 weeks or so to stop stinking that paint was horrible. If your interested I can figure out the company I went with for our converters im really happy with them in our cherokees other than stinky paint. My friend runs and owns a transmission shop and me and him went over options and he really liked this company where I got the blue ones from I believe it was 350 or 400 dollars i remember seeing a large price difference between some you definitely dont want to go cheap. I'd be sure to research where you're torque converter is coming from to make sure it's USA made with quality parts or at least made with quality parts. I think some of the smaller companies would be my first pick nowadays. Some big name brand companies that have been in the transmission industry for years source their stuff as cheaply as possible. I know there's at least 2 or 3 high quality replacement converters I found when researching online. I'd definitely get one from a torque converter specialist or high end company because they see lots of abuse in our rigs. Also if you happen to find cracks in the flex plate inspect the replacement very well to make sure it matches, I had a friend who replaced his flex plate with a new one from oriellys and there was a difference in the crank position sensor pickup ring that caused the engine not to run. It took me a while to diagnose that issue.
@@fabguy276 Before you pull off the transmission to get to the converter, pull the pan and test the solenoids. One of the two controls torque converter lockup, and if it's bad, it could be causing the issue. This was the issue I had, converter was new, but still wouldn't lock up. It was the solenoid. MUCH easier to get to, and I think cheaper to fix also.
@@shanesaw13 thanks for the advice. Fortunately the converter does lockup in 3rd & 4th but it won’t lockup if I have too much pedal pushed down. I can hear it lockup and see the RPM’s drop 500-700rpm.
I ran something very similar I made a skid plate with 1/4 wall 1x1 tube and a some expanded steel. Now I have a manual tho
Something is likely wrong with your transmission/torque converter if it is not locking up in low gears. It could also be the trans controller that's in the cab is faulty (maybe try this first). My 1990 has just a basic parts store cooler after the one built in the radiator cooling it, 33's but on 3.73 gears, 4.7 stroker but it never gets above 220 in the California heat. I don't go easy on the throttle, I roll 85+ all the time on the highway, when I'm off road it gets the same punishment. If you can't keep the temps down, put the cooler in front of the radiator like everyone else does, they don't restrict air flow that bad.
100% I believe my TC is damaged and causing too much slippage. I could be wrong, but I don’t think the AW4 TC has lockup capabilities in 1st & 2nd gear from everything I have read. My tc locks up just fine but only in 3rd & 4th gear. Keep in mind most Jeepspeed 4.0’s on 35’s need to run a $800 Trans cooler that looks like a mini radiator and they still run at 250f in a sand wash. It seems the AW4 just runs hot. Nevertheless, I am certain that if I rebuilt my tranny and put a new tc in, it would make a huge difference.
@@fabguy276 It might not have it in 1st, but it definately has it in 2nd and up, I think it might only lock up in 2nd if you have the shifter locked in 2nd
Or you could put gears in it , 4:56s would ease the strain on the trans.
That’s exactly what it has front and rear.
I've got one tranny cooler on my 96 but it's not as modified as yours is the only thing that I've done minor stuff to it I've got stock gears so I'm only running 30s and it's two-wheel drive so I don't have a pumpkin up front 3-inch lift it's definitely a lot lighter than yours so maybe I'm not putting a lot of strain on the tranny but I've separated the fluids radiator worries about the engine and the cooler is for the tranny I know that the aw4 is super tough but I still havent looked at temps I need to get a gauge I live in Redlands so it doesn't get as hot up the hill where your at I know yucca still gets hot
Hey FabGuy, have you tried upping the trans fluid viscosity to better match rotational speeds in torque converter and lock up easier ? Something like Lucas trans Stop Slip. Meant to help with temps too.
I have been running Royal Purple Max ATF and have noticed it has helped a little.
Have you changed the torque converter or is it original? I beat on a cherokee with 33s and stock gearing for years and eventually the torque converter blew up like literally blew up. I know youve mentioned having 4.10s or 4.56s i forget so it should be close to stock with your 35s and not too hard on it. One thing i was thinking is your converter could be slipping more than its supposed to they do wear out. When my converter blew i overhauled my whole transmission but everytime i have a high milaege xj apart i put a new converter in it.
You may be dealing with a worn out converter thats slipping too much but is still able to lock. What i look for in that instance is lots of heat and if the fluid is getting dirty or kinda burnt smelling. It might be worth it to replace the torque converter. I was thinking maybe your lockup solenoid was malfunctioning but it sounds like it locks up no problem. If you were to ever replace a solenoid do not run aftermarket ones you want new oem asin ones or used ones they are easy enough to bench test. I think you should keep working on the xj everyone has a jk heavily modified and dialed in xjs are really cool but you have to work hard for it sometimes.
Its kinda tough for me to judge your heat issue because of your sand driving and stuff but i compare it to when i used to drive my cherokee years ago with 33s and stock gearing i had heavy bumpers and armor and a spare tire on the roof etc.. plus i would haul a trailer with 2 dirtbikes and i just had 1 tranny cooler or 2 smaller ones for a little while and i very rarely saw over 180 on the trans temp and that was on the road going over the mountain pass with dirtbikes in tow trying to go 60 mph. Then theres been lots of other instances over the years where i really ran it very hard i daily drove it for like 6 years or so with stock gears and 33s in that form until the converter let go. Mine never made heat it just blew apart. Im also running royal purple max atf i think thats one of the best fluids for the aw4. If you ever have it apart for something I'd change the torque converter for sure and inspect the flex plate for cracks. If your up for it you may want to take it apart specifically to replace the torque converter and give it a try. There are some high end converter companies that have one for an aw4 i remember looking and i found a website that sorta specialized in aw4 stuff also the a340 in the supra is the same transmission essentially. Its worth it spending the extra money on a high quality converter. Also if you do take it apart to do the converter thats a good time to replace the original freeze plug in the back of the block behind the flexplate and block plate with a brass one if its original its a pain when those rust through if you have rust in your system.
You may not have any issues so it might not be worth it to tear into it unless you can really pin point it. But it kinda sounds like its slipping too much and creating more heat. I know in diesel trucks ive experienced bad torque converters in the same way they seem to work just fine but build up lots of heat and you can really tell when you try to spool it up and get on torque theres just nothing much there it doesn't get up and go like it should it will go pretty good but not like it should ive dealt with that a few times. Ive actually replaced quite a few torque converters over the years and theres been a few that have been difficult to diagnose because the performance didn't seem to be down that much but once it was replaced you could definitely tell.
This is a long comment lol but anyways it seems to be coming along nicely i like the roof rack.
Thanks for the time and insight. I’m going to agree with you and say it’s the converter for sure. My dad told me the same thing. I guess that is my next project….
@@fabguy276 if the converter comes painted it may be a good idea to brake clean off the paint my last one was painted blue and it was stinky as it burned off which is normal for things like freshly painted engines and parts and such but for whatever reason it took like 3 weeks or so to stop stinking that paint was horrible. If your interested I can figure out the company I went with for our converters im really happy with them in our cherokees other than stinky paint. My friend runs and owns a transmission shop and me and him went over options and he really liked this company where I got the blue ones from I believe it was 350 or 400 dollars i remember seeing a large price difference between some you definitely dont want to go cheap. I'd be sure to research where you're torque converter is coming from to make sure it's USA made with quality parts or at least made with quality parts. I think some of the smaller companies would be my first pick nowadays. Some big name brand companies that have been in the transmission industry for years source their stuff as cheaply as possible. I know there's at least 2 or 3 high quality replacement converters I found when researching online. I'd definitely get one from a torque converter specialist or high end company because they see lots of abuse in our rigs.
Also if you happen to find cracks in the flex plate inspect the replacement very well to make sure it matches, I had a friend who replaced his flex plate with a new one from oriellys and there was a difference in the crank position sensor pickup ring that caused the engine not to run. It took me a while to diagnose that issue.
@@fabguy276 Before you pull off the transmission to get to the converter, pull the pan and test the solenoids. One of the two controls torque converter lockup, and if it's bad, it could be causing the issue. This was the issue I had, converter was new, but still wouldn't lock up. It was the solenoid. MUCH easier to get to, and I think cheaper to fix also.
@@shanesaw13 thanks for the advice. Fortunately the converter does lockup in 3rd & 4th but it won’t lockup if I have too much pedal pushed down. I can hear it lockup and see the RPM’s drop 500-700rpm.
Which cooler did you get? Trying to lower my temps on my ZJ
I have 5 trans coolers! LOL
Are you still selling your XJ? I saw your post on autotrader but it won’t let me contact you
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