How do you fix the speedometer? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

GMCjunkie · 07-05-2002, 08:26 AM

In the stepside (70 gmc) It just sits there

How do I go about fixin it??
Thanks

71Chev · 07-05-2002, 08:39 AM

Is the speedo cable good? Hooked up on both ends?

May need a new cable or a new speedo or both.

dwaite72lnghrn · 07-05-2002, 08:48 AM

I would start and see if the cable is connected at both ends and is not rusted through anywhere. Hook a drill up to the trans end of the cable an spin it and see if the speedometer runs. This will tell if it is a cable, speedo problem or the gear in the trans if it is the trans gear when you go to get one tell the your gear ratio and trans type. Alot of times the cable breaks and the speedo will not move when the drill is run(you need a reversible drill I think).If it does not run disconnect from the back of speedo and run the drill on the trans end and see if the cable turns. If it turns speedo problem if it doesn't cable problem. Hope this helps
good luck on your trip.

Gordo · 07-05-2002, 08:54 AM

You need to determine which part is at fault, gears, cable or speedo head. Does the odometer still register and not the speedometer? If so than I would blame the head. If nothing registers, reach up behind dash and disconnect cable from head, pull it down where you can see it, go for a drive and take note if the cable insert is turning, if not you can remove the insert out through the cable (not always nesesary to replace intire cable/sheath) and inspect for damage. this insert can be replaced easily, (don't forget to lube it when you install it). If there is no damage to the cable, your problem may be at the trans drive or driven gears. Jack up and support the rear of truck (this minimizes fluid loss) removec cable, remove small bolt and clamp holding sleeve, then gently pull the sleeve out, this will give you access to the drivin gear, inspect for damage. Seldom does the drive gear get damage, but you can eye-ball it through the opening to see if it is damaged or not. To replace the drive gear would require removing the driveshaft and tail extension housing from the trans, not a big deal but probally not nesesary.

Longhorn Man · 07-05-2002, 12:36 PM

And if you end up pulling out the little gear, you'll see it is color coded for easy ID. I know I have a spare white one you can have if needed...just swing by here on your way to GA.

junkyardjohn · 07-05-2002, 12:56 PM

IF IT IS INDEED THE SPEEDO HEAD, & YOU NEED ANOTHER ONE, EMAIL ME & I'LL SEND YOU ONE (I'M SURE I HAVE A COUPLE LYING AROUND) FOR THE POSTAGE. (WE'LL CONSIDER IT A HOUSEWARMING PRESENT) LOL

GMCjunkie · 07-07-2002, 08:32 AM

Thanks everyone for you help, Ive printed out alla your info. Dont think we're gonna get to this real soon, lol. Got our yard sale goin on this weekend, (oh thrills

) Then one more week til we head to Ga~!!!!!! Thanks again,
Yaller AWSOME!!!

07-05-2002, 08:26 AM	#1
GMCjunkie Dude...I'm a CHICK Join Date: Jul 2000 Location: Lakeland Georgia Posts: 6,192	How do you fix the speedometer? In the stepside (70 gmc) It just sits there How do I go about fixin it?? Thanks __________________ ~~~~~~~~~~~~~* "The unexamined life is not worth living" -Socrates ~~~~~~~~~~~~~* '71 GMC Suburban 4x4

07-05-2002, 08:39 AM	#2
71Chev Senior Member Join Date: Dec 2000 Location: Indiana Posts: 3,074	Is the speedo cable good? Hooked up on both ends? May need a new cable or a new speedo or both. __________________ 71 Chevy CST Long Fleet 350/350/3.07 leaf rear.

07-05-2002, 08:48 AM	#3
dwaite72lnghrn Registered User Join Date: Jun 2002 Location: central pa Posts: 1,525	I would start and see if the cable is connected at both ends and is not rusted through anywhere. Hook a drill up to the trans end of the cable an spin it and see if the speedometer runs. This will tell if it is a cable, speedo problem or the gear in the trans if it is the trans gear when you go to get one tell the your gear ratio and trans type. Alot of times the cable breaks and the speedo will not move when the drill is run(you need a reversible drill I think).If it does not run disconnect from the back of speedo and run the drill on the trans end and see if the cable turns. If it turns speedo problem if it doesn't cable problem. Hope this helps good luck on your trip. __________________ 72 longhorn c30 502BB/th400/fact air/4.11rear/ custom camper 72 bug(the better half's) under reconstruction 2009 HHR aqua blue 71 GMC k20 350/sm465 2009 Chevy hd3500 6.6 Victory Red crew cab dually Dave & Jeanne

07-05-2002, 08:54 AM	#4
Gordo Registered User Join Date: Jan 2001 Location: Killingworth, CT. USA Posts: 3,378	You need to determine which part is at fault, gears, cable or speedo head. Does the odometer still register and not the speedometer? If so than I would blame the head. If nothing registers, reach up behind dash and disconnect cable from head, pull it down where you can see it, go for a drive and take note if the cable insert is turning, if not you can remove the insert out through the cable (not always nesesary to replace intire cable/sheath) and inspect for damage. this insert can be replaced easily, (don't forget to lube it when you install it). If there is no damage to the cable, your problem may be at the trans drive or driven gears. Jack up and support the rear of truck (this minimizes fluid loss) removec cable, remove small bolt and clamp holding sleeve, then gently pull the sleeve out, this will give you access to the drivin gear, inspect for damage. Seldom does the drive gear get damage, but you can eye-ball it through the opening to see if it is damaged or not. To replace the drive gear would require removing the driveshaft and tail extension housing from the trans, not a big deal but probally not nesesary. __________________ 1971 C10 swb stepside 350/700R4/3.73posi (retired as of 4/22/03) 1998 S10 short bed 2002 S10 Blazer 1942 Oldsmobile 1958 Massey Harris Pony 1951 Wife Killingworth, Connecticut May those who love us, love us, any of those who do not love us, may God turn their hearts. And if God is unable to turn their hearts, may he turn their ankles so we may know them by their limping. A man who works with his hands is a laborer; a man who works with his hands and his brain is a craftsman; but a man who works with his hands and his brain and his heart is an artist.

07-05-2002, 12:56 PM	#6
junkyardjohn Registered User Join Date: Aug 2001 Location: SOMERSET KY. Posts: 6,425	IF IT IS INDEED THE SPEEDO HEAD, & YOU NEED ANOTHER ONE, EMAIL ME & I'LL SEND YOU ONE (I'M SURE I HAVE A COUPLE LYING AROUND) FOR THE POSTAGE. (WE'LL CONSIDER IT A HOUSEWARMING PRESENT) LOL __________________ junkyardjohn 69 1 TON TOW TRUCK // 84 4WD CUCV BLAZER// 85 1 TON 4WD STAKE TRUCK// 86 M1031 5/4 TON 4WD CUCV// ALOT OF OLD TRUCKS FOR ONE OLD MAN TO DRIVE. THERES ROOM FOR ALL OF GODS CREATURES RIGHT NEXT TO MY MASHED POTATOES// LIFE MEMBER OF P.E.T.A (PEOPLE EATING TASTY ANIMALS) DON'T RENT U-HAUL ALWAYS TELL THE TRUTH IT WILL AMAZE PART OF THE PEOPLE & ASTONISH THE REST

07-05-2002, 12:36 PM	#5
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,690	And if you end up pulling out the little gear, you'll see it is color coded for easy ID. I know I have a spare white one you can have if needed...just swing by here on your way to GA.

07-07-2002, 08:32 AM	#7
GMCjunkie Dude...I'm a CHICK Join Date: Jul 2000 Location: Lakeland Georgia Posts: 6,192	Thanks everyone for you help, Ive printed out alla your info. Dont think we're gonna get to this real soon, lol. Got our yard sale goin on this weekend, (oh thrills ) Then one more week til we head to Ga~!!!!!! Thanks again, Yaller AWSOME!!! __________________ ~~~~~~~~~~~~~* "The unexamined life is not worth living" -Socrates ~~~~~~~~~~~~~* '71 GMC Suburban 4x4

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