1. Welcome to PlowSite. Notice a fresh look and new features? It’s now easier to share photos and videos, find popular topics fast, and enjoy expanded user profiles. If you have any questions, click HELP at the top or bottom of any page, or send an email to help@plowsite.com. We welcome your feedback.

    Dismiss Notice

TCC Lockup

Discussion in 'Chevy Trucks' started by JB, Apr 17, 2000.

  1. JB

    JB Member
    Messages: 46

    The lockup on my 1988 K-5 Blazer with the 700-R4 transmission locks up between 50-55mph. My 87 K-10 with the same transmission locks up at 45mph and most of my other trucks that I have had locked up at that speed also. Is there an adjustment to make the lockup come on at 45mph or so? Any info would be appreciated. Thanks in advance, JB
     
  2. yortengel

    yortengel Senior Member
    Messages: 123

    Check and Readjust the TV Cable. Its the only adjustment I know of.
     
  3. JB

    JB Member
    Messages: 46

    I'll adjust the TV cable tommorow and hope I can get it to go into OD at around 45. Thanks, JB
     
  4. John DiMartino

    John DiMartino PlowSite.com Veteran
    Messages: 2,154

    Lockup is electronicly controlled on the TBI models.I have slightly altered the lockup points by adjusting the TPS on these trucks,as well as TV cable.You might have to live with it or change the computer chip.Lockup is affected by TPS,coolant temp,road speed(VSS)and MAP sensor readings.A couple of springs in the valve body to. If your computer wont allow lockup until 53 mph,adjusting the TV cable or TPS is useless.Most people would be happy to have TCC lockup at 55mph,most chug to much at 40mph in lockup in OD.under light throttle my 89 GMC 2500 will lockup at 31mph in 3rd,shift to OD at 35 mph and stay locked up chugging along at idle speed.<p>----------<br>John D<br>
     
  5. JB

    JB Member
    Messages: 46

    John, Thanks for the info. It seems everything is so complex these days. I was thinking of buying a Sensor Tester to check various sensors. Have you or anyone else had any experience with one? I've heard that you can also use a voltage testor also for the same use as long as it is 10 megaohms. JB
     
  6. yortengel

    yortengel Senior Member
    Messages: 123

    I use a Fluke DVOM of all my testing, But what makes you think that you have a sensor going bad? I think that sensor testers are a lot overrated. You can test just about anything with a DVOM.
     
  7. JB

    JB Member
    Messages: 46

    What is a DVOM? JB
     
  8. yortengel

    yortengel Senior Member
    Messages: 123

    Digital Volt Ohm Meter. I do a lot of electrical diagnostic work. so I bought a Fluke. which is one of the best brands, But there are some good ones out there for a lot less money.
     
  9. JB

    JB Member
    Messages: 46

    I have one, a SUNPRO. I did nt know you could use it for a sensor tester. I mainly use to test volts, ohms and as a tach. JB
     
  10. plummermark2002

    plummermark2002 Member
    Messages: 30

    tranny swap

    I HAVE A QUESTION ABOUT SWAPPING A 400 TRANNY FOR A 350 I HAVE A 1982 CHEVY SCOTTSDALE3/4 TON WITH A 350 ENGINE & A TH350 TRANSMISSION I WANT TO CHANGE IT TO A TH 400 TRANNY IT CAME OUT OF A 3/4 TON CHEVY OF SAME YEAR EXCEPT IT WAS A DIESEL ENGINE, WAS TOLD OT WOULD NOT BE TO HARD I WOULD JUST HAVE TO CHANGE THE TORQURE CONVERTER AND THE SHIFT POINTS IN THE VALVE BODY, COULD YOU PLEASE TELL ME HOW I WOULD GO ABOUT CHANGING THE SHIFT POINTS IN THE VALVE BODY, AND ALSO I NOTICED THAT THE TH350 HAS A DETENT CABLE HOOKUP IS THIS GOING TO EFFECT THE WAY THE TRANNY WORKS NOT HAVING THE CABLE HOOKED UP ?ANY HELP WITH THIS WOULD BE APPRECIEATED. PLUMMERMARK
     
  11. The Boss

    The Boss 2000 Club Member
    Messages: 2,099

    If you look, the posts above yours are almost 4 years old. I'd put your question under a new topic and you'll probably have better luck.:waving: