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  • 4L60E falling out of lockup

    So I have this little problem with my '99 Camaro, I just had the trans rebuilt and I have to say it is working great......feels tight, shifts great and I really couldn't be happier with the way it runs, well except for one thing.....For some reason the converter will lockup and then within a mile of driving it will unlock and stay that way for another mile of driving and then lockup again, where sometimes it stays locked up and other times it unlock again after a bit of driving........I have the Lockup set to engage at 38 mph, so anything over that the converter should stay lockup up, and I'm usually going about 45mph when the convert unlocks, though I've had in do it at freeway speeds to, but not as much as it does in the lower speeds...... Also I've had this problem for a while now, it did it with the last rebuild..........And yes I went and talked with my trany guy about it, but I'd like to get some others opinions on this before I tell you what we've decided to do.........

    So what is the most common problem with 4l60e's when it comes to falling out of lockup??

  • #2
    bad stop light switch
    fix it or fry fourth gear

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    • #3
      Well I say the problem is its an automatic...... and when it goes out the second time like my 700 r4 the fix will be to convert it to a stick like I did. LOL in all seriousness.... hope you get it figured out. I do have a 4L60E / Lt1 in the wagon .I have a follow up follow up question when you get your answer.
      Previously HoosierL98GTA

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      • #4
        Ok a little update on the situation.........So far I replaced the TCC valves in the valve body and pump, with aftermarket valves....I guess both valves move in their bores and wear the bores out causing pressure to bleed by.....The Valve for the valve body removes the PWM and just makes the TCC circuit a simple on/off control........ The one for the pump has a Teflon seal and to eliminate cross leaking of converter signal oil and converter feed oil........After doing these two fixes, the trans seems to shift better, but it still will fall out of lockup.......Next I replaced the brake light switch as Spidey recommended(I also had someone else recommend this.....But sadly it still falls out of lockup......I was also told that a bad TPS can cause it to fall out of lockup, so I replaced that, but it seems with my car because it has traction control that I have to do a TPS learn procedure that requires a Tech 2 scan tool........I replaced the Throttle body a long time ago and never new about having to have the TPS re-calibrated.....So my question is could the lockup falling out of lockup be caused by the TPS not being calibrated??

        I will say that after replacing the two valves, the TPS and brake light switch that the lockup works more frequently, but it still wants to drop out of lockup with doing around 45mph with very light throttle(cruise).......When it does fallout it seems that it takes a "Time Period" before it will engage again.......

        Any info on how to fix this would be appreciated.......I'm going to try to get the TPS calibrated today, I'm hoping that that takes care of the problem....If it doesn't I'm just not sure what could be causing this.........

        Here's the Sonnax Valve that goes into the Pump.....

        4L60E,4L65E NEW SONNAX 77805E -K TCC APPLY VALVE FOR ALL PWM TRANSMISSIONS. THIS IS A NEW NEVER OPENED SONNAX TCC APPLY VALVE KIT FOR THESE AUTOMATIC TRANSMISSIONS;. NEW SONNAX 77805E-K TCC APPLY VALVE KIT WITH ONE TEFLON SEAL AND ONE SPRING.


        And here's the aftermarket valve that goes into the Valve Body......

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        • #5
          On a Ford and I use that because its what I know and most work the same way.

          The converter and shifts are load based. It can be a learend stratigy also, when the trans starts to fail it might learn to add more pressure to lock a gear up or shift timing change. When a repair is done, the PCM still has the learned patern in it, and will need a hard reset or it will not shift correct.

          Are you sure this is a issue on a load sense trans shift? Your throttle input under a load will tell the PCM to down shift so it does not lug overdrive at 45 and down shift on tip in does not sound unreasonable to me. Do you have a Data stream to watch which shows loads like a Ford does? It did not just fall out if it waited till you gave input, a Ford without input will coast down from 80 to 18 mph in OD till you touch the throttle then down shift. Last have you went to a dealer to see if there is a recalibration for it. Remember these dont think for thereselves its all match up. No Cables to move to taylor it to a customer at this level of tune
          2007 SBN/A Drag Week Winner & First only SBN/A Car in the 9's Till 2012
          First to run in the .90s .80s and .70's in SBN/A
          2012 SSBN/A Drag Week Winner First in the 9.60's/ 9.67 @ 139 1.42 60'
          2013 SSBN/A Drag Week, Lets quit sand bagging, and let it rip!

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          • #6
            A little update here for you guy on this, the trans still has an intermittent lockup, I took it to a guy a friend of mine recommended and he put it on his Tech 2 and we drove the car, he said everything looked ok, nothing was standing out that would cause it......He also said the computer was commanding it off when it unlocked.......So I did some more research, and came across an article on LS1.com, where a guy from a trans shop was saying that it was caused by the computer detecting misfires....apparently you can have misfires that don't set a misfire code, but will be enough to cause the trans to command the lockup to be unlocked.......I did a bit of data logging today and it does show misfires going on, it doesn't trip the code for them, but when the lockup disengages it doesn't register them on my screen until the lockup engages again, which makes me feel there is a correlation between the two......The guy in the LS1.com thread, said to max out the misfire tables in the programming and that should take care of it......So I guess that is what is going to be my next step........

            Anyone else ever here of misfires causing the lockup to disengage??......

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            • #7
              I can't contain the sarcasm.... you mean there are misfires that don't throw codes? OMG, really!!! there are some here who might doubt you when you say that

              The computer is only as good as its sensors - are you certain that the computer is getting good info? I presume there's an error routine that says "when X occurs" do not let lock-up occur. Has the transmission been doing this ever since it's been rebuilt?
              The flow chart that I've seen for lockup converters says that there has to be a bunch of "yes" responses for the torque converter to lock up (speed over __, TPS at >____%, etc), what it sounds like is one of the sensors says "yes" then "no" then "yes" (meaning there maybe a break in the circuit somewhere). Maybe check the wires to the transmission?

              and to make the problem even more general - the problem misfire in my GTO was the plug wire and spark plug
              Last edited by SuperBuickGuy; March 5, 2012, 05:11 PM.
              Doing it all wrong since 1966

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              • #8
                Ya data logging can show you many things, I was surprised to at the amount of misfires it logged and it wasn't just on one cylinder though 5 and 6 seemed to register more than the rest........As for the wiring and sensors I've replaced all the electronics in the trans and the TCC lockup solenoid comes with the complete trany wiring harness, even comes with the plug that goes in the case. I've had the trans rebuilt twice and it's done it with both rebuilds, but like the one guy said, the computer is commanding the TCC off, so it's not something that in the trans, but more in the info the computer is getting from the other sensors like your saying......I also have to check with the dealer, my factory manual on the car states that if you replace the TPS, that you have to recalibrate it using a Tech 2 like the dealer uses, but when the guy at the trans shop tried to do it, his Tech 2 didn't give him a TPS learn option, so we'll see what the dealer has to say on that.........I'm seriously thinking of buying a Tech 2 for myself as my old Snap On seems a bit dated.......

                Anyway I'm going to play with my tune a little, I need to fine tune my part throttle shift points and I'll max out the misfire tables and see if that stops if form falling out.......

                And a little more research and I think I have my answer.......Seems I'm not the only one to have this problem.....Maybe it's those MSD coils, DG always did say they were junk, I guess it might be time to check the plugs and plug wires.........

                This article describes what's happening to me........

                Last edited by TC; March 5, 2012, 08:28 PM.

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                • #9
                  it was amazing how little arcing caused such a problem on my car. I should have taken pictures of the plug wire, ah well, hindsight is 20/20.

                  Did you replace the wires and plugs when you put the MSD coils on?
                  Last edited by SuperBuickGuy; March 5, 2012, 09:36 PM.
                  Doing it all wrong since 1966

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                  • #10
                    Originally posted by SuperBuickGuy View Post
                    it was amazing how little arcing caused such a problem on my car. I should have taken pictures of the plug wire, ah well, hindsight is 20/20.

                    Did you replace the wires and plugs when you put the MSD coils on?
                    I replaced them when I put the headers on, a few years ago, I have those E3 plugs and MSD super conductor wires.......

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                    • #11
                      Ditch the E3 plugs and get something conventional.
                      Escaped on a technicality.

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                      • #12
                        Originally posted by TheSilverBuick View Post
                        Ditch the E3 plugs and get something conventional.
                        I was thinking the same thing, just go back to the stock plugs that are recommended for it........

                        Though the misfires could be due to me not fine tuning the AFR's after the modifications that I've done.......and I'm not going to worry about that since I'll be doing a cam swap here shortly and have the car tuned on a dyno by a local LS1 tuner.......
                        Last edited by TC; March 6, 2012, 12:56 PM.

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                        • #13
                          Easily can be too lean mis-fires if the AFR's logged during the mis-fires were 15+:1.
                          Escaped on a technicality.

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                          • #14
                            WooHooo!!!!!!! Happy Days!!!!!!!!!

                            Maxed out the misfire tables in HPTuners and bam no more falling out of lockup!!!!! I've only done one test drive but it held every time. I'm going to take a longer trip a little later so we'll see if it holds up.......

                            I also did a couple of other adjustments to the mid rpm shift points and TCC duty cycle.......

                            Now it's time to do some data logging and start fine tuning the timing curve........

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                            • #15
                              Update on the Update, the lockup is still working correctly, hasn't fell out in days.......To think it was just the misfire tables......

                              I also adjusted my part throttle shift points, basically allowing it to hang longer in 2nd and 3rd gear before the shift, while i'm giving it 1/4 to 1/2 throttle, I've got 2nd holding to 45mph and third holding to 60mph, it sure gets on the go now......

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