4l60e trouble, slipping in overdrive only.. computer issue?
4l60e trouble, slipping in overdrive only.. computer issue? Just got done rebuilding a 4l60e that was slipping in and out of 4th gear. It is still doing it. I'm starting to wonder if it is tune related as the engine has had problems relating to the tune
the vehicle is a jeep wrangler that was swapped in a 5.3L and a 1999 4l60e. The PCM is off a 99 trans-am I think and previously (due to it being a 99 PCM and it using a 2002 camaro wiring harness) the engine ran horrible and it needed to be tuned to correct the o2 sensors.
So I'm starting to wonder if it is in the computer. When 4th gear slips- it doesn't feel like a normal slip. It catches and moves and then every second or so it acts as if it goes into neutral then back into 4th then to neutral (it does this continuously when giving it throttle at 55mph +). Almost as if the torque converter is locking and unlocking.
is there a simple way to test and see if the torque converter is staying locked? I have an obd2 scan tool, but I don't think I can see if the TCC is locked or not using it.
THANKS FOR ANY HELP!
the vehicle is a jeep wrangler that was swapped in a 5.3L and a 1999 4l60e. The PCM is off a 99 trans-am I think and previously (due to it being a 99 PCM and it using a 2002 camaro wiring harness) the engine ran horrible and it needed to be tuned to correct the o2 sensors.
So I'm starting to wonder if it is in the computer. When 4th gear slips- it doesn't feel like a normal slip. It catches and moves and then every second or so it acts as if it goes into neutral then back into 4th then to neutral (it does this continuously when giving it throttle at 55mph +). Almost as if the torque converter is locking and unlocking.
is there a simple way to test and see if the torque converter is staying locked? I have an obd2 scan tool, but I don't think I can see if the TCC is locked or not using it.
THANKS FOR ANY HELP!
Well on the converter you have 2 things to monitor for TCC the TCC ENABLE and the PWM % Unless you used the transgo shift kit then the PWM is mostly eliminated. As for the TCC enable you can ties an LED in. One side to the tan wire with black stripe the other side to B+ 12 VOLTS when the TCC enables the LED should light up. (note must be and LED 12v NOT A TEST LIGHT) On the PWM you will have to find a way to look at data unless its like i said eliminated in the build. More than likley you will however find the answer in the TCC enable.
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Well on the converter you have 2 things to monitor for TCC the TCC ENABLE and the PWM % Unless you used the transgo shift kit then the PWM is mostly eliminated. As for the TCC enable you can ties an LED in. One side to the tan wire with black stripe the other side to B+ 12 VOLTS when the TCC enables the LED should light up. (note must be and LED 12v NOT A TEST LIGHT) On the PWM you will have to find a way to look at data unless its like i said eliminated in the build. More than likley you will however find the answer in the TCC enable.
is the tan/black located at the brake switch or do I need to go to the plug at the transmission?
and if the LED goes off every time it slips, then it IS in the tune?
Thanks for the help
also- I hope it's not the servo/band issue, as I made sure that was correct lol
Yes the wire is at the trans and yes when it goes off lockup was disabled by the tuning. the tan/blk is grounded when it on so you will want neg side of LED to it.
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I took it to a transmission shop, he hooked up a special computer to it and pulled some codes that werent throwing the check engine light. One of them was brake switch low voltage or something. He also said that the computer isn't showing any brake signal for the torque converter. I'm wondering if the shop that installed the wiring harness didn't connect the brake switch to the right wire. Would that cause a symptom like what I described?
the transmission shop said it also might be the servo as Predator T/A menchined. Can I access/fix that without taking the transmission out of the vehicle? or do I need to have the transmission on its back to mess with it
also, the guy didn't have time to have the computer plugged in and go for a drive to see if the TCC was acting up because of the tune
thanks again guys
the transmission shop said it also might be the servo as Predator T/A menchined. Can I access/fix that without taking the transmission out of the vehicle? or do I need to have the transmission on its back to mess with it
also, the guy didn't have time to have the computer plugged in and go for a drive to see if the TCC was acting up because of the tune
thanks again guys
Ok guys, I plan on checking out the brake switch connection tomorrow. Hopefully that will fix it, but I'm not counting on it doing the job.
I think it might be more of a problem with the servo. As when I installed it- it was a little hard to turn the output shaft, which I think is a band thing. I've been looking up info about the servo and everything. I have one question, what does this mean
"proper band clearance is 1/16" to 1/8" " where is this measured?
The band and reverse input drum on this transmission were completely toasted when I took it apart for the rebuilt. Does this mean that whoever rebuilt it last time, didn't correct the band clearance - making the band grab the input drum too hard?
I think it might be more of a problem with the servo. As when I installed it- it was a little hard to turn the output shaft, which I think is a band thing. I've been looking up info about the servo and everything. I have one question, what does this mean
"proper band clearance is 1/16" to 1/8" " where is this measured?
The band and reverse input drum on this transmission were completely toasted when I took it apart for the rebuilt. Does this mean that whoever rebuilt it last time, didn't correct the band clearance - making the band grab the input drum too hard?
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I think I found out how the "band clearance" is measured, is it the amount the servo cover can be pushed in once the retaining clip is installed to hold it in. If this is true, then my cover moves in 1/2" which is way too much. Any advice on what I should do?
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^ you are right on the clearance. I'm not sure how it can actually be measured though. Use the guesstimate gauge? If it is a 1/2" it sounds to be waaay too much. Sounds like maybe the servo "pin" tip may have worn out.
my built 4L60E did the same thing, servo clearance opened up. I added a washer to the servo to make up some pin-to-band clearance and it worked a little while longer. I was feeling lucky one day and added another washer and while I was driving ended up breaking the transmission case at the servo bore. You can tighten up the clearance, but I recommend just having a shop rebuild it.
my built 4L60E did the same thing, servo clearance opened up. I added a washer to the servo to make up some pin-to-band clearance and it worked a little while longer. I was feeling lucky one day and added another washer and while I was driving ended up breaking the transmission case at the servo bore. You can tighten up the clearance, but I recommend just having a shop rebuild it.
I wired up a new brake switch, I checked the one that was installed on it from the shop that did the engine swap- and the transmission was NOT getting 12v when the brake is not pressed in. I wired up a new switch and took it for a test drive and it didn't seem to slip at all in over drive
Could the brake switch have been the problem? would it cause something similar to slip on and off on and off in over drive?
Could the brake switch have been the problem? would it cause something similar to slip on and off on and off in over drive?
Did you make sure during your rebuild that the valve body spacer plate was not worn where the check ***** sit. There is one that wears really bad and I think it will cause a slip in overdrive. There is also a few other check ***** in the case and in the input drum that can get worn and cause slippage. I wouldn't think that the brake switch with no power applied would cause the converter to give erratic converter application. Hopefully its fixed though I rebuilt mine at the same time as you and I know how it feels to have so much time and effort into something you don't know is going to work.
Did you make sure during your rebuild that the valve body spacer plate was not worn where the check ***** sit. There is one that wears really bad and I think it will cause a slip in overdrive. There is also a few other check ***** in the case and in the input drum that can get worn and cause slippage. I wouldn't think that the brake switch with no power applied would cause the converter to give erratic converter application. Hopefully its fixed though I rebuilt mine at the same time as you and I know how it feels to have so much time and effort into something you don't know is going to work.
I know what you mean as the brake switch wouldn't seem like it would really be the problem, a couple posts up I was saying how it most likely will not be it because it just seems too much of an easy fix lol plus how it only does it in over drive is fishy
and yeah, it sucks going through the pain of pulling the transmission, rebuilding it and installing it back in and it still be doing the same thing!
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Yeah, the holes didn't look too beaten up. I even took it to a transmission shop to get a 2nd opinion on them
I know what you mean as the brake switch wouldn't seem like it would really be the problem, a couple posts up I was saying how it most likely will not be it because it just seems too much of an easy fix lol plus how it only does it in over drive is fishy
and yeah, it sucks going through the pain of pulling the transmission, rebuilding it and installing it back in and it still be doing the same thing!
I know what you mean as the brake switch wouldn't seem like it would really be the problem, a couple posts up I was saying how it most likely will not be it because it just seems too much of an easy fix lol plus how it only does it in over drive is fishy
and yeah, it sucks going through the pain of pulling the transmission, rebuilding it and installing it back in and it still be doing the same thing!
