88 Jeeper
NAXJA Forum User
- Location
- Charlotte, NC
I've been having issues with my transmission on my 4.0L 4x4 XJ for several years now and it never really bothered me as I had another vehicle as daily driver, but now I am driving the XJ more and want to fix the issues. 280K miles...
Multiple Symptoms:
First off, in the cooler seasons in NC the transmission works like it is supposed to. When it hits 70+ degrees out, it starts acting up.
Problem 1 -
Converter remains locked in the D and 3 positions when you let off the gas, and stays locked when shifting gears (it will shift based on vehicle speed/load, but not unlock the TC). It does not lock in 1 and 2, as I don't think it is supposed to normally. The brake pedal switch will cause the converter to unlock. No amount of heavy accelerating or coasting seems to make it want to unlock. Often, when I come to stop and then take off again, it seems to work fine for several minutes, up to an hour. Also, if I put it in neutral and then back in D or 3, it still stays locked up once it goes back in gear. If I turn the engine off and then back on (sitting still or moving in neutral), it seems to fix the problem for a period of time.
Problem 2 -
Converter will not lock up unless under full throttle condition. Problem exists in D or 3 under driving conditions where the converter should normally lock up. If I am on the highway, when my converter is locked traveling 65mph, RPMs = ~2000 normally. When the converter is unlocked, RPM is between 2250 and 2750 depending on the road (hill, wind, drag, etc.). If I step on the gas hard, the converter will lock, but as soon as I let up a little to maintain a cruising speed, it unlocks and the RPMs rev up. Same thing in 3rd gear, and at 40mph when the converter would normally lock up at this speed without much load on the engine. If I turn the engine off or come to a stop, the problem sometimes fixes it self for some period of time. It may be coincidence, but it seems if I accelerate hard (2500+ rpm) in first or 2nd gear (before the trans starts acting up), it seems to make the tranny angry and problem 1 or 2 will occur.
Solutions - I suspect many will say replace/reset the TPS. All the checks I've done suggest that the TPS is ok, and it is at the right voltage levels. Whatever this problem is, it is electrical for sure. I don't know how to check and intermittent TPS though short of permanent alligator clips and measure voltage real time in the cab! It is also strange that the problem is dependent upon the external ambient temp. Has anyone had this problem before? Anything to look at other than replacing the CPS? Trans speed sensor? Problem now is my converter seal / oil pump seal is now leaking, so I am considering the retro fit of a 91-95 XJ trans. Anyone know if all of the AW4 converters are interchangeable from year to year?
Thanks
Multiple Symptoms:
First off, in the cooler seasons in NC the transmission works like it is supposed to. When it hits 70+ degrees out, it starts acting up.
Problem 1 -
Converter remains locked in the D and 3 positions when you let off the gas, and stays locked when shifting gears (it will shift based on vehicle speed/load, but not unlock the TC). It does not lock in 1 and 2, as I don't think it is supposed to normally. The brake pedal switch will cause the converter to unlock. No amount of heavy accelerating or coasting seems to make it want to unlock. Often, when I come to stop and then take off again, it seems to work fine for several minutes, up to an hour. Also, if I put it in neutral and then back in D or 3, it still stays locked up once it goes back in gear. If I turn the engine off and then back on (sitting still or moving in neutral), it seems to fix the problem for a period of time.
Problem 2 -
Converter will not lock up unless under full throttle condition. Problem exists in D or 3 under driving conditions where the converter should normally lock up. If I am on the highway, when my converter is locked traveling 65mph, RPMs = ~2000 normally. When the converter is unlocked, RPM is between 2250 and 2750 depending on the road (hill, wind, drag, etc.). If I step on the gas hard, the converter will lock, but as soon as I let up a little to maintain a cruising speed, it unlocks and the RPMs rev up. Same thing in 3rd gear, and at 40mph when the converter would normally lock up at this speed without much load on the engine. If I turn the engine off or come to a stop, the problem sometimes fixes it self for some period of time. It may be coincidence, but it seems if I accelerate hard (2500+ rpm) in first or 2nd gear (before the trans starts acting up), it seems to make the tranny angry and problem 1 or 2 will occur.
Solutions - I suspect many will say replace/reset the TPS. All the checks I've done suggest that the TPS is ok, and it is at the right voltage levels. Whatever this problem is, it is electrical for sure. I don't know how to check and intermittent TPS though short of permanent alligator clips and measure voltage real time in the cab! It is also strange that the problem is dependent upon the external ambient temp. Has anyone had this problem before? Anything to look at other than replacing the CPS? Trans speed sensor? Problem now is my converter seal / oil pump seal is now leaking, so I am considering the retro fit of a 91-95 XJ trans. Anyone know if all of the AW4 converters are interchangeable from year to year?
Thanks