Page 2 of 5 FirstFirst 12345 LastLast
Results 21 to 40 of 90

Thread: Having issues with tcc slip while commanding 0. 8l90 circle d triple disc

  1. #21
    ha just saw your reply after I posted mine

  2. #22
    I may have went overboard but should be disabled now right? thanks for your help
    Attached Files Attached Files

  3. #23
    Advanced Tuner
    Join Date
    Aug 2010
    Location
    Detroit, MI
    Posts
    926
    Not the best practice to reverse the hysteresis, putting the min above the max. Depending on how the code is structured, it could cause issues. If you have to have a window of operation for something you don't want enabled, just move it far away from where you'll be operating.

  4. #24
    ok that's very good to know. the factory torque min and max was fashioned this way so I just ran with it. so using your logic this should be more like what you are describing... I think.
    Attached Files Attached Files

  5. #25
    Advanced Tuner
    Join Date
    Aug 2010
    Location
    Detroit, MI
    Posts
    926
    There you go, that works. Now go drive it.

  6. #26
    Quote Originally Posted by smokeshow View Post
    There you go, that works. Now go drive it.


    I drove it and it still isnt seeing more than 45psi at cruise and ramping up with throttle input.

  7. #27
    Advanced Tuner
    Join Date
    Aug 2010
    Location
    Detroit, MI
    Posts
    926
    Quote Originally Posted by DENALI62 View Post
    I drove it and it still isnt seeing more than 45psi at cruise and ramping up with throttle input.
    But is it actually slipping? What feedback are you getting from the truck physically, seat of the pants..

  8. #28
    Quote Originally Posted by smokeshow View Post
    But is it actually slipping? What feedback are you getting from the truck physically, seat of the pants..

    I can feel it shuddering. It used to be constantly while cruising. Now with all the tuning and experimenting ive gotten it to be useable at a steady cruise but attempt to accelerate at all and it shudders.

  9. #29
    Advanced Tuner
    Join Date
    Apr 2019
    Location
    Parts store
    Posts
    476

    8-speed shudder

    Quote Originally Posted by DENALI62 View Post
    I can feel it shuddering. It used to be constantly while cruising. Now with all the tuning and experimenting ive gotten it to be useable at a steady cruise but attempt to accelerate at all and it shudders.
    8-speed shudder symptom.

    I know some GM 8 speeds have a shudder. According to TSB (Technical Service Bulletin) 18-NA-355, the latest update addresses torque converter clutch (TCC) shudder conditions on 8L45 and 8L90 eight-speed automatic transmissions, RPO codes M5N, M5T, M5U, and M5X. Affected vehicles include Chevrolet, GMC and Cadillac vehicles. https://gmauthority.com/blog/2019/08...sion-problems/

    However, a new fluid flush appears to fix the issues, with some customers beginning to report a dramatic change in shift quality after swapping out the old juice. If the flush doesn?t fix the issue, the next step may be to replace the torque converter, which could be glazed.

  10. #30
    Quote Originally Posted by Hondaeater View Post
    8-speed shudder symptom.

    I know some GM 8 speeds have a shudder. According to TSB (Technical Service Bulletin) 18-NA-355, the latest update addresses torque converter clutch (TCC) shudder conditions on 8L45 and 8L90 eight-speed automatic transmissions, RPO codes M5N, M5T, M5U, and M5X. Affected vehicles include Chevrolet, GMC and Cadillac vehicles. https://gmauthority.com/blog/2019/08...sion-problems/

    However, a new fluid flush appears to fix the issues, with some customers beginning to report a dramatic change in shift quality after swapping out the old juice. If the flush doesn?t fix the issue, the next step may be to replace the torque converter, which could be glazed.


    I appreciate that. I have the new new fluid in a fresh trans and a circle d converter. Back in 2015 when i bought the truck it had "the shudder" and i went through all the triple flushes and updated torque converter jazz. It did help. Pain in the butt though.

  11. #31
    I feel like im getting somewhere at least. Its nice to be able to cruise in 7th gear on the highway for a change. I just wish i could get consistent unvaried pressure. I feel that ben is right that there has to be some tables/parameters that we simply dont have access to. Or there is an OS issue.

  12. #32
    Advanced Tuner
    Join Date
    Aug 2010
    Location
    Detroit, MI
    Posts
    926
    Have you talked to Chris about this? Can't imagine that an aftermarket torque converter would slip under conditions where the stock one doesn't. Unless, the clutch is already burned... If that's the case, it may never really lock up and will need to be rebuilt.

  13. #33
    Quote Originally Posted by smokeshow View Post
    Have you talked to Chris about this? Can't imagine that an aftermarket torque converter would slip under conditions where the stock one doesn't. Unless, the clutch is already burned... If that's the case, it may never really lock up and will need to be rebuilt.


    I totally agree. Since the converter was new it has done this. I have talked to chris about it and he wants me to send it in. Im sure i will eventually. I have not let it slip much the only time i have ever let it lock is when trying to tune out the slip. Im gonna let it ride for a while with the current tune and just check the fluid quality periodically. Thanks for all your help and insight. Im cruising in 7th at 55 with no vibrations just have to kick down manually to pass which is a big improvement to cruising in 6th sometimes 5th depending on wind and incline lol.

  14. #34
    one last thing. any thoughts on why it is commanding 10rpm slip at random?

  15. #35
    Advanced Tuner
    Join Date
    Apr 2007
    Posts
    330
    Even when I zeroed out my commanded slip, I would still get +/-10rpm slip as others have said I think its just noise if its under 10 rpm. So you have the latest Mobil 1 Synthetic LV fluid with the blue label? I had the "triple flush" procedure done on mine and it cam back within a year or so, I dropped the pan and filled up with the blue label fluid and it has fixed it so far. I don't think the blue label fluid has even been available for a year or so. The associated TSB says you also have to use a certain flush machine to get all the fluid out of everything including the cooler lines as well and completely replace with the blue label fluid.

  16. #36
    Quote Originally Posted by cmitchell17 View Post
    Even when I zeroed out my commanded slip, I would still get +/-10rpm slip as others have said I think its just noise if its under 10 rpm. So you have the latest Mobil 1 Synthetic LV fluid with the blue label? I had the "triple flush" procedure done on mine and it cam back within a year or so, I dropped the pan and filled up with the blue label fluid and it has fixed it so far. I don't think the blue label fluid has even been available for a year or so. The associated TSB says you also have to use a certain flush machine to get all the fluid out of everything including the cooler lines as well and completely replace with the blue label fluid.

    Yes i have blue label fluid in a new trans. 10rpm may be undiscernable with a stock 'verter but with the triple disc it shudders. Fyi pace performance has the best deal on the new fluid. Im pretty sure there is some physical problem with my converter.

  17. #37
    I am trying to get control of my tcc pressure too especially at wot. It would be great if the tables had the desired effects. The bidirectional control is able to lock it up and hold a ton of power so it isn’t a mechanical issue.
    2017 camaro ss a8 with low mount twins

  18. #38
    Quote Originally Posted by parish8 View Post
    I am trying to get control of my tcc pressure too especially at wot. It would be great if the tables had the desired effects. The bidirectional control is able to lock it up and hold a ton of power so it isn?t a mechanical issue.

    You arent kidding when i clicked the button for tcc lockup on the scanner the pressure jumped straight to 594psi i freaked out like omg shes gonna blow!

  19. #39
    Quote Originally Posted by DENALI62 View Post
    You arent kidding when i clicked the button for tcc lockup on the scanner the pressure jumped straight to 594psi i freaked out like omg shes gonna blow!
    I have been told there is no actual pressure sensor. No idea what the actual pressure is. I am going to get busy trying to bypass the ecm and trigger it directly. I know I can get control of that noid and get it to lock but it sure if I can keep the trans from going into limp mode because it sees something weird.
    2017 camaro ss a8 with low mount twins

  20. #40
    Quote Originally Posted by parish8 View Post
    I have been told there is no actual pressure sensor. No idea what the actual pressure is. I am going to get busy trying to bypass the ecm and trigger it directly. I know I can get control of that noid and get it to lock but it sure if I can keep the trans from going into limp mode because it sees something weird.
    Thats an interesting bit of knowledge and it makes sense i mean there isnt a part/sensor that reads tcc line pressure that im aware of.