Dismiss Notice

Welcome To CK5!

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

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

Speedometer STUCK at times while driving

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by fausz, Mar 20, 2002.

  1. fausz

    fausz Registered Member

    Joined:
    Jun 27, 2001
    Posts:
    16
    Likes Received:
    0
    Location:
    Wake Forest, NC 27587
    I recently purchased a 1976 K5, 350/350, all stock including tires. The speedometer will stick at different speeds. For instance, I may really be driving 70, but the needle points to 40! But, it doesn't just stick at that speed, or any specific speed for that matter. Any ideas? Thanks in advance!
     
  2. 85HeartBurb

    85HeartBurb 1/2 ton status

    Joined:
    Jan 10, 2002
    Posts:
    735
    Likes Received:
    0
    Location:
    Temecula, south
    i'm having the same problem with my 74 ihave a 454/350 combo but my milage still tracks correctly i'm thinking something is making the needle stick?!?!
     
  3. chevyfumes

    chevyfumes Court jester

    Joined:
    Feb 24, 2000
    Posts:
    38,586
    Likes Received:
    271
    Location:
    Watch for the muzzleflash!
    If you guy's are talkin' about where the speedo goes into the transfer case ,then I had the same problem on my 74, try clipping some of the cable off at where it gos into the transfer case , I discovered this when my buddy had me put the transfer case in nuetral and the E brake on and then the truck wont move when you give it gas and he slowly pulled out the cable after he unscrewed it and it started to work perfectly, so we snipped about a 1/4" off the end, and it's worked fine ever since...Just be careful../forums/images/icons/wink.gif
     
  4. dyeager535

    dyeager535 1 ton status Premium Member

    Joined:
    Dec 13, 2000
    Posts:
    27,490
    Likes Received:
    339
    Location:
    Roy WA
    Sticking at speeds is gonna be in the speedo head assembly. Unfortunately I know of no fix for this, the phone book will have speedometer shops listed though. Noise is something mine makes when it wants to act up. Thinking of going electronic because of it : )

    Bouncing speedo is a symptom of a cable problem.
     
  5. chevyfumes

    chevyfumes Court jester

    Joined:
    Feb 24, 2000
    Posts:
    38,586
    Likes Received:
    271
    Location:
    Watch for the muzzleflash!
    Mine wasn't bouncin' it was stickin' foo * fumes in his best Mr. T voice* /forums/images/icons/laugh.gif
     
  6. dyeager535

    dyeager535 1 ton status Premium Member

    Joined:
    Dec 13, 2000
    Posts:
    27,490
    Likes Received:
    339
    Location:
    Roy WA
    BTW, "T" says to get some "kable eaze" if you want to make SURE the speedo cable isn't causing any problems. At least it can't hurt to make sure the cable isn't going to be causing any problems or noise, like they typically do.
     
  7. fausz

    fausz Registered Member

    Joined:
    Jun 27, 2001
    Posts:
    16
    Likes Received:
    0
    Location:
    Wake Forest, NC 27587
    I pulled the speedo cable out last night from the speedo end. I had the truck up on jack stands and got the wheels turning and watched the needle/screw, it turned consistently. Because it turned consistently, my next guess is that it's the gear that the needle/screw goes into at the back of the speedometer. I've been told that they're plastic gears and sometimes get stripped. This would explain why the needle sticks sometimes. Thanks for everyone's help, I'll post back my results!
     
  8. ramjet gmc

    ramjet gmc CK5 Staff Staff Member Moderator GMOTM Winner

    Joined:
    Dec 19, 2001
    Posts:
    3,372
    Likes Received:
    2
    Location:
    Milltown NJ 08850 NJ sucks
    The Speedo is fine its that darn 65 mph on the side of the road your stuck on /forums/images/icons/wink.gif
     
  9. Blue85

    Blue85 Troll Premium Member

    Joined:
    Jul 26, 2000
    Posts:
    9,562
    Likes Received:
    849
    Location:
    Grand Rapids area
    Build(s):
    1
    This has to be a problem with the speedometer itself. The reading is just a balance between a return to zero spring and the force exerted by the magnet spinning with the cable. The cable and gear can't cause it to stick. If they stop spinning, the needle should go to zero.
     
  10. 1975Jimmy

    1975Jimmy 1/2 ton status Premium Member

    Joined:
    Jan 23, 2015
    Posts:
    186
    Likes Received:
    98
    Location:
    SoCal
    Would love to know if anybody ever had luck simply spraying some silicone lube on the speedo assembly to loosen the needle wheel up. My speedo sticks when it's hot out and when it gets stuck it doesn't move back to zero until the interior cools down.
     
  11. Blue85

    Blue85 Troll Premium Member

    Joined:
    Jul 26, 2000
    Posts:
    9,562
    Likes Received:
    849
    Location:
    Grand Rapids area
    Build(s):
    1
    Wow, 15 years back from the dead. But it's better than 50 threads about the same thing.

    So I've had both problems. The bad cable caused bouncing and kept the cruise control from working properly. I tried the kable-ease with limited success, but when I finally replaced the speedo cable, I took the old one apart and found it it had come partially unwound somewhere in the middle, which was making it stick against the casing, no doubt. You can pull the cable out of the casing to check it and then slide it back in, BTW. With a good cable, the cruise works fine, even if the speedometer doesn't. Currently, it takes my speedo about 5 miles to get up to 55MPH (no, my truck isn't this slow). After driving for a bit, it seems to work normally, but does sometimes take a few seconds to reach 0 again after a stop. I know I put some kind of lube on it years ago and the problem sort of went away for awhile. I suspect there is some secret lube that will keep it working longer-term.
     
  12. 1975Jimmy

    1975Jimmy 1/2 ton status Premium Member

    Joined:
    Jan 23, 2015
    Posts:
    186
    Likes Received:
    98
    Location:
    SoCal
    Well, my cable is new, and is routed perfectly with no hard bends or binds and just for kicks I tested the cable and it spins freely in the sheath. I also removed the cable from behind the speedo, and sprayed a healthy amount of silicone lube on the assembly on the back of the speedo and reattached the cable. This time making sure the cable end wasn't jammed up against the speed magnet shaft. I think this may have been causing friction. I took it for a drive yesterday and the speedo seemed to work without failing. Time will tell if this cured the problem.
     

Share This Page