Dismiss Notice

Welcome To CK5!

Registering is free and easy! Hope to see you on the forums soon.

Score a FREE t-shirt and membership sticker when you sign up for a Premium Membership and choose the recurring plan.

More stupid tach questions

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by Cavalry, Feb 25, 2001.

  1. Cavalry

    Cavalry 1/2 ton status

    Joined:
    Oct 1, 2000
    Posts:
    978
    Likes Received:
    0
    Location:
    upstate NY(although I cant figure out why)
    I found a factory tach cluster junkyarding, stole it for $10. Only problem is the tach is screwed up (still got my $10 bucks worth of stuff though) It reads around 3K at idle, but seems to work otherwise. Whats the chances that I can just pull the needle and calibrate it with another tach? Were these known to slip? Can anyone rebuild it for less than a used one costs?


    Luke
    84 K5
    [​IMG]
     
  2. Goose

    Goose 1/2 ton status

    Joined:
    Feb 17, 2000
    Posts:
    1,127
    Likes Received:
    1
    Location:
    South Central Kansas
    Back in High School I had a '77K5 with a factory tach that didn't work. I could tell what resistor burned up and took it to a good friend (older) that had his own electric company. He said that it would be very difficult to fix unless he had all the schematics for the original tach circuits. Basically needed the original blueprints if you will to fix it. I really doubt you could just move the needle. If I was you, I would do some serious research into the original circutry and then take it to someone who knew what they were doing.

    [​IMG]
     
  3. mudpuppy89k5

    mudpuppy89k5 Registered Member

    Joined:
    Nov 3, 2000
    Posts:
    44
    Likes Received:
    0
    Location:
    Marietta, Ga
    A buddy put a factory tach in my '89 back when it was new. He was a mechanic for one of the Pontiac dealerships at the time and really knew his stuff (still does). To set the tach needle, he pulled it off the pin, then we turned the ignition switch on without starting the engine to get zero rpm. He pushed the needle back on the pin aligned with the zero rpm on the tach. Worked fine ever since. Hope this helps.

    John Perry
    http://www.mudpuppy.coloradok5.com/
     
  4. HarryH3

    HarryH3 1 ton status Author

    Joined:
    May 31, 2000
    Posts:
    10,384
    Likes Received:
    2
    Location:
    Georgetown, TX
    Cool deal! I look inside every GM truck I ever see in a junkyard. I have yet to find one that has a factory tach! [​IMG]

    <font color=black>HarryH3 - '75 K5</font color=black>
    <A target="_blank" HREF=http://ThunderTruck.ColoradoK5.com>http://ThunderTruck.ColoradoK5.com</A>
     
  5. Grim-Reaper

    Grim-Reaper 3/4 ton status Author

    Joined:
    Feb 17, 2000
    Posts:
    7,385
    Likes Received:
    0
    Location:
    Atlanta
    Won't work on these tachs. Mine reads 1,100 at idle 1500 off and 7,000 at hwy speeds when it's turning about 3k. Most of them the spring (theres a name for it can't remember it) one or both have broken and it doesn't give the physical resistance needed. There are companies that will rebuild them but it's like $100. www.yearone.com has that information.

    Diging it in the dirt with my K5's
    Grim-Reaper
    <A target="_blank" HREF=http://grimsk5s.coloradok5.com/>http://grimsk5s.coloradok5.com/</A>
     

Share This Page