1. If you have recently registered with a gmail email address, you must contact me, as gmail will not forward our confirmation email to you. Contact me and jim@trishieldperformance.com to complete your registration.
    Dismiss Notice
  2. In and effort to reduce the spam on the site, several years ago I had went to a program where I manually approve each and every new registration. This approval gives you full access to the site, to pictures, and to post, among other things. To be able to enjoy the full potential of the board for you, you need to be fully registered.. and that's easy.. Just send an email to me at jim@trishieldperformance.com and I will verify your registration. This policy will remain in effect indefinitely, as it has completely eliminated the bad actors from our site, who would spam and hack it, once they gained access. Thanks JW
    Dismiss Notice
  3. The "Group Buy" for the 1967-68 Deluxe Steering wheel recasting is now officially "Open". Now is the time to start sending in the wheels. The latest date that the wheels must be received by Kochs is 31 March 2025 The cost for each wheel is $750. The only "up front cost" is your shipping the wheel. If you send in more than one wheel, each additional wheel will cost $700. Shipping and insurance to Kochs and return shipping will be extra. You will be contacted by Teresa to make payment for the wheel(s) and return shipping and insurance when your wheel(s) is complete. The shipping will be factored on your delivery address and insurance. I will be sending the contact information all of you have sent me to Teresa at Kochs. Send in your wheels, horn pad and hardware and paint color sample if applicable. Please include: First and Last Name Shipping Address Phone number email address V8Buick "Member Name" Wheel Color (SEE THE BOTTOM FOR WHEEL COLOR) Pease read the "shipping to Kochs" below. There are two addresses. One for USPS Mailing One for FedEx and UPS shipping You can use USPS/Mail, UPS or FedEx to send in your core. Use the appropriate address depending on what service you use to ship. If you use USPS/Mail ship to: Koch's P.O. Box 959 Acton, CA 93510 Attn: Teresa If you use UPS or FedEx ship to: Koch's 7650 Soledad Canyon Road Acton CA 93510 Attn: Teresa Kochs Contact: Teresa (661) 268-1341 customerservice@kochs.com Wheel Color If you wheel is Black, you can list that in your information you send in with your wheel. For colored wheels, please contact Teresa about specifics for wheel color if you do not send in a color sample to match. Please contact me if you have any questions. Thank you to everyone for your participation in making this a reality. And "Thank You" Jim Weise, for allowing and facilitating this project! Michael .................... to remove this notice, click the X in the upper RH corner of this message box
    Dismiss Notice

Unable to stop my Turbo 400 from shifting

Discussion in 'The "Juice Box"' started by JCP, Apr 17, 2024.

  1. JCP

    JCP Well-Known Member

    Question for you guys. I have a 1970 Riviera BT coded T400 in my GS. If I manually downshift the transmission in to 1st gear, give the car full throttle, the transmission will upshift to 2nd gear on its own before I have moved the shifter to the 2nd gear position. So I can downshift with the shifter, I just can't control upshifts at WOT. Any thoughts on why this is? All the other Turbo 400's I've had, held a given gear at wide open throttle, until I moved the shifter.
     
  2. Canadian GS 350

    Canadian GS 350 Well-Known Member

    Stock turbo 400 will shift to 2nd when governor reaches its shift point. The transgo shift kit includes mods to have full control of shift points. Im sure GM did this on stock turbo 400 to protect the tranni. I believe you can modify the stock valve body to stay in chosen gears. Others will chime in with more experience.
     
    JCP likes this.
  3. telriv

    telriv Founders Club Member

    IF the electrical downshift wire is not connected OR your NOT getting FULL throttle at electrical downshift switch for the trans. so the throttle is NOT providing enough pedal travel for the electric downshift switch will short shift at WOT.
    Otherwise starting in 1965 TH400's were designed to shift at 5500 RPM's even if the lever was in number 1 position.
    This was designed to save engines & excessive engine warranty replacements even on Chevy's.

    Tom T.
     
    Max Damage and JCP like this.
  4. Matt69olds

    Matt69olds Well-Known Member

    Watch this:

     
    JCP likes this.
  5. Matt69olds

    Matt69olds Well-Known Member

    Keep in mind, once you do the 1-2 shift valve modifications, if the shifter is in first you will drive over the crankshaft and it still won’t shift.

    Ifyou are going a 100mph and pull the shifter into first gear, it’s going into first!
     
    patwhac, Max Damage and JCP like this.
  6. JCP

    JCP Well-Known Member

    Thanks for the replies. So I guess the transmission is doing what it's supposed to do. Looks like I might want to modify the governor to raise my shiftpoints.
     
    Max Damage likes this.

Share This Page