Page 1 of 9 123 ... LastLast
Results 1 to 10 of 83

Thread: Why does 1st gear slam into 2nd? 4L80E translplant

  1. #1
    Senior Member 1SlowHoe's Avatar
    Join Date
    Apr 2006
    Posts
    117

    Default Why does 1st gear slam into 2nd? 4L80E translplant

    Long drawn out story but the short version is:
    I swapped my 60E to an 80E. Both 2WD. My original OS did not support an 80E. I did a segment swap from another OS. My 1-2 up shift is ridiculous. It will break the tires loose at 10mph and cause people to spill their drinks. I have replaced the valve body in the trans with one setup by a trans builder I trust (Finish Line Transmission). I double checked the 2nd VSS to make sure it was wired to the PCM correctly. The trans has an updated TransGo HD shift kit, drilled to the middle setting. It also slams into 4th at part throttle sometimes.
    I have adjusted all the tables I understand with no luck. The very first shift in the morning is perfect when the trans is cold. After it has made a few shifts, it’s hard as hell. This leads me to think it has something to do with the transmission fluid temp tables. I don’t know enough about what drives final transmission line pressure to know what I’m doing. Any help is appreciated. My current tune is attached.
    Been dealing with this for about 3 years and enough is enough….
    Would swapping to a custom OS solve this? How do I do that?

    Chris
    Attached Files Attached Files
    Driving a truck with a BLOWN engine has two meanings. I get to experience BOTH on a regular basis
    2006 GTO....in progress
    2002 6L/80E/Radix/ Tahoe

  2. #2
    Lifetime Member 5.7ute's Avatar
    Join Date
    Oct 2006
    Posts
    1,840

    Default

    Have you looked through this thread. There is some important info in relation to a kitted trans.http://forum.efilive.com/showthread.php?t=1723&page=2
    The Tremor at AIR

  3. #3
    Joe (Moderator) joecar's Avatar
    Join Date
    Apr 2003
    Posts
    28,403

    Default

    Hi Chris,

    Have a look at table D0704.

    A custom OS will do the same thing.

    Also, follow what 5.7ute said, try setting shift times tables D1108-10 to zero.

  4. #4
    Senior Member 1SlowHoe's Avatar
    Join Date
    Apr 2006
    Posts
    117

    Default

    THANKS GUYS, LOOKING NOW, AT D0801 AND D0704...
    Driving a truck with a BLOWN engine has two meanings. I get to experience BOTH on a regular basis
    2006 GTO....in progress
    2002 6L/80E/Radix/ Tahoe

  5. #5
    Senior Member 1SlowHoe's Avatar
    Join Date
    Apr 2006
    Posts
    117

    Default

    D0704:
    The pressure control solenoid (or force motor) is controlled by the PCM by varying the current flow to the solenoid.
    The PCM can vary the current from 0.0 amps (high pressure) to 1.1 amps (low pressure).

    I have negative numbers in this table. How does that work? Should I be raising these numbers to LOWER line pressure?
    Driving a truck with a BLOWN engine has two meanings. I get to experience BOTH on a regular basis
    2006 GTO....in progress
    2002 6L/80E/Radix/ Tahoe

  6. #6
    Senior Member 1SlowHoe's Avatar
    Join Date
    Apr 2006
    Posts
    117

    Default

    One place says 1108-10 to be 0.0 and another says .2
    I made some big changes to D0704. Am I off track?
    Driving a truck with a BLOWN engine has two meanings. I get to experience BOTH on a regular basis
    2006 GTO....in progress
    2002 6L/80E/Radix/ Tahoe

  7. #7
    Lifetime Member 5.7ute's Avatar
    Join Date
    Oct 2006
    Posts
    1,840

    Default

    I havent had any real experience with tuning auto's.(Only done the one stock box)
    From my understanding the tables D1108-10 need to be set to zero to allow the shift kit to do its job. Otherwise the adaptive learning will try to take over control of the shifts, which it cannot since the shift kit has taken this function away.
    This usually results in weak line pressure & a ruined trans in a short amount of time, I am not sure if it can cause a high pressure issue but the possibility is there.
    Also, are you sure there are no DTC's in the log?
    The Tremor at AIR

  8. #8
    Senior Member 1SlowHoe's Avatar
    Join Date
    Apr 2006
    Posts
    117

    Default

    No DTC's that I can find. I am about to upload and test drive to see if the changes made any difference. Be right back.
    Driving a truck with a BLOWN engine has two meanings. I get to experience BOTH on a regular basis
    2006 GTO....in progress
    2002 6L/80E/Radix/ Tahoe

  9. #9
    Senior Member 1SlowHoe's Avatar
    Join Date
    Apr 2006
    Posts
    117

    Default

    No difference
    Driving a truck with a BLOWN engine has two meanings. I get to experience BOTH on a regular basis
    2006 GTO....in progress
    2002 6L/80E/Radix/ Tahoe

  10. #10
    Lifetime Member jfpilla's Avatar
    Join Date
    Apr 2003
    Posts
    666

    Default

    I realize your not getting any codes. But since nothing is working so far, you might try setting E0802 to 50.
    2003 red vert
    Mods:
    LS7 crate engine, wet sump, 24xx reluctor
    LPE 100mm MAF
    Vararam, cold air intake and bridge
    RPM Level 6/4L60e trans
    3.42 gears
    Yank SS3600
    1-7/8" AR headers
    Z06 exhaust
    470rwhp 437rwtq
    1/8th mi-1.526-60'-6.862-1/8th-@100.74mph

Page 1 of 9 123 ... LastLast

Similar Threads

  1. 4l80e 4th gear and tcc problem (running from 4L60E segment)
    By kkustomz in forum 4speed RWD/FWD Transmission Tuning (incl T42)
    Replies: 35
    Last Post: November 28th, 2011, 01:05 PM
  2. manual gear selection overide 4l80e
    By 2500ak in forum 4speed RWD/FWD Transmission Tuning (incl T42)
    Replies: 4
    Last Post: January 6th, 2010, 03:48 PM
  3. 4l80e help
    By da69fishman in forum 4speed RWD/FWD Transmission Tuning (incl T42)
    Replies: 6
    Last Post: December 9th, 2008, 11:21 PM
  4. 4L80E 2nd & 3rd gear only
    By rickwils51 in forum 4speed RWD/FWD Transmission Tuning (incl T42)
    Replies: 4
    Last Post: November 1st, 2007, 05:06 AM
  5. 4L80E 4rth Gear problem
    By almusafir in forum 4speed RWD/FWD Transmission Tuning (incl T42)
    Replies: 18
    Last Post: March 14th, 2007, 01:43 AM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •