4l60e 1996 tahoe transmission problems help!!!!

Discussion in 'GM Powertrain' started by JOHNNYBLACKEYE, Oct 12, 2009.



    Need some help .have 4x4 tahoe 1996 transmisson wont shift to 2nd unless i have it right at 3ooo rpm and let off gas.also have no overdrive isnt sliping in any gears and pulls just fine .i have been reading up on this site about the 4l60e trans troubleshooting a few guys said to change the 1-2 shift sensor did that afew guys said to change t.p.s did that has fresh fluid and filter in it all the wireing looked good inside pan. There was smoe metal shaveings on the magnet when i did the sensors.....any guess on where to look next any help will be great thanks in advance ALSO THERE IS NO CODES

    sorry about the caps sent from phone
    thanks john
    Last edited: Oct 12, 2009
  2. Jimmiee

    Jimmiee Epic Member 5+ Years 1000 Posts

    You can throw parts at it all day long and never fix it. Why not scan it for codes and fix the problem? Also since you have a 96 it probably needs the GM PCM Ground Wire Update.

    This bulletin is being reissued to ensure that correct procedures are followed for this condition. Please discard Corporate Bulletin Number
    66-71-03A (Section 7 -- Automatic Transmission).


    When performing a transmission replacement labor operation K7000 on these vehicles with a 4L60-E or 4L80-E, you must include front chassis wire repair labor operation N6112. Inspect the VCM to verify the latest part number revision (16244210).

    Condition Some owners may comment that the automatic transmission has either a slip or flare on the 1-2 and/or 2-3 upshift, or no 3rd or 4th gear, or launch shudder. Upon investigation, the technician may find a DTC P1870 stored in the VCM.

    Cause A poor internal ground between the two circuit boards of the VCM may cause the VCM to command erratic line pressure at the pressure control (PC) solenoid valve.

    Correction Using harness jumper wire and instruction kit, P/N 12167310, revise the wiring harness at the VCM connector. Corrections were made to the VCM beginning 2/14/96. The corrected VCMs are identified with service number
    16244210 on the VCM identification label.

    Procedure The following is a summary of the instructions included with the service kit:

    1.. Remove the negative terminal from the battery.
    2.. Move the wire located at connector J3 (WHITE/GREY/CLEAR), pin 18 to connector J1 (BLUE), pin 23.
    3.. Install the jumper wire between connector J2 (RED), pin 26 and connector J3 (WHITE/GREY/CLEAR), pin 18.
    4.. Install the tag included in the kit around the VCM wiring harness. This tag notes that the wiring harness has been modified.
    5.. Reconnect the negative battery terminal. Road test to verify that the condition has been corrected. If any of the following conditions are noted, the transmission should be repaired or replaced using the most cost effective method. Canadian dealers should repair the transmission.

    . Transmission fluid oxidation or excessive sediment.

    . Transmission slip or flare after this service fix is performed.

    . DTC P1870 is stored on a 4L60-E (M30).

    The following tools are available from Kent-Moore (1-800-345-2233) for use in removing and relocating the VCM wires:

    . J 41758 Terminal Tool; used to remove the wire from the VCM connector.

    . J 41759 Punch; used to punch a new hole through the connector seal.

    Parts Information Part Number Description Qty

    12167310 Harness Jumper Wire Kit


    Well i did the jumper wire from the dealer it still does the same thing !no codes and same problem any other help would be great
  4. Jimmiee

    Jimmiee Epic Member 5+ Years 1000 Posts

    If you can get someone to scan it and watch the data you may find your problem. It may be a bad MLP or VSS. A scanner will show what's happening.
  5. brianj

    brianj Rockstar

    Sounds like a vehicle speed sensor. However, most of the time this will post a code.You realy need to have this scanned for codes. Shotgun mechanics gets very expensive very quickly. You said that there are no codes. Did you hook up a scanner or are you just relying on no check engine light? you can have codes that will not set the engine light, and many of them are in the tranny.If you have no codes, you are probably looking at internal problems. there is a good site to look up diagnostics- google ATRAonline and you will find them. Good luck.
  6. Billyk82

    Billyk82 New Member

    Have a 96 tahoe 5.7 4x4 recently the transmission started having issues from 1st gear to 2nd at about 3000 rpm if u feathered the gas it would switch ...now just today it got its self stuck in 1st gear no matter what I do it won't switch ...just wondering if I should go through the trouble of just swapping out transmissions or play the trouble shooting game
  7. Billyk82

    Billyk82 New Member

    Had the transmission diagnosed the computer relays the shift info ..?the solenoids work but no shift ...even shifting manually does nothing .....trans shop wanted 1500 to rebuild ...I declined opting to find a transmission on my own ...lucky for me today the local pick n pull just got a 96 yukon 5.7 4x4 with only 146 000 kms on it ...it was in a head on collision went in dropped the transmission today ...upon first inspection the seals look new the atf looks smells and yes even tastes relatively new ...so fingers crossed tomorrow I drop the transmission in my tahoe and attempt the installation
  8. thegawd

    thegawd Rockstar 2 Years 1000 Posts

    well your always rolling the dice on a used tranny but sometimes it works out in your favor. iv installed 2 used tranny the first one didnt fail before I sold the truck and the second was in the 97 which lasted 20 000 kms before it gernaded. what happened in your tranny is the most common failure in 4L60E's, the sunshell gear was fractored, chewed all the splines off or broke in half. it links 1st, 3rd and reverse. this part is made from an unhardened steel when oem, there is an after market one from monster transmission called the beast, over built, hardened and made to last. this is the best sunshell gear on the market. when my last tranny blew I had it rebuilt a stage 3 heavy duty and the only oem part is the case. after you get the used tranny installed I would personally start looking at getting your old tranny rebuilt in a similar way, a lot stronger anyways than oem. and go very easy on the used tranny and pull heavy loads in 3rd.

  9. dadymurano

    dadymurano New Member

    I've had good luck with low millage used transmissions. Like 70,000 miles or less. It'd be great if you could change out the most used clutch packs and front seal while it's out. I wish I was a good tranny guy.
    Good luck.

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