Help with speedo - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Slammed70 · 05-31-2009, 11:45 PM

Been awhile since I posted on the boards...

I dont know if this should go in the drivetrain or the electronic section...so I'm posting it here.

As the name, I got a '70 truck. Now, my speedo is "jumpy" as in it wont steadily increase when the speed changes. How do I fix this? Also, how do I change the cable, the truck isnt near me, or anywhere near me at the moment. Its over an hour away and I want to have it pictured in my head how to do it. How does it route from the back of the cluster out of the cab?

Thank you.

JimKshortstep4x4 · 06-01-2009, 05:14 AM

The cable routes from the back of the speedometer out the firewall and down to the transmission. It might help the jumping needle if you remove the inner cable and lube it with a light grease.

All you have to do is unscrew the cable housing from the back of the speedometer and pull the inner cable out, lube and reinstall.

Jim

**Stocker** · 06-01-2009, 10:01 AM

^^ I agree. I thought I pulled mine out from the bottom (transmission) end, but it's been so long ago, I may be wrong about that.

Once you get it out, clean it up the best you can. I lubed mine with a lightweight white lithium grease, but I understand graphite lube is better, especially in colder climates.

**LockDoc** · 06-01-2009, 10:36 AM

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I just re-lubed the one in the White Truck. I didn't unscrew it at the bottom. just unscrew the housing from the speedo, work it around the wires and stuff until you can pull it below the dash and pull out the cable. Pull slowly and don't force it or you will ruin the cable. If you feel a lot of resistance, spray some solvent/cleaner down the housing and work the cable back and forth until it loosens up enough to pull it out. Wash the cable off with thinner or solvent of some kind, let it dry and lube it with a light oil. When you insert the cable back into the housing twist it as you push it the last little bit to make sure it seats into the transmission speedometer gear....

LockDoc

cdowns · 06-01-2009, 11:17 AM

auto parts stores have speedo cable lube//graphite based it polishes the inside of the cable housing with use doesn't harden up and gives a longer life to cable

**LockDoc** · 06-01-2009, 11:36 AM

Quote:

Originally Posted by cdowns

auto parts stores have speedo cable lube//graphite based it polishes the inside of the cable housing with use doesn't harden up and gives a longer life to cable

The graphited cable lube works great if people use it with moderation and it doesn't get any moisture in it. Be sure and shake the container good before you use it, don't use any more than you absolutely have to, and don't let it get wet or it turns into a gummy mess...

LockDoc

msgross · 06-01-2009, 11:42 AM

good advice guys.. thanks.

06-01-2009, 05:14 AM	#2
JimKshortstep4x4 Senior Member Join Date: Jul 2001 Location: Muskegon,MI,USA Posts: 6,026	Re: Help with speedo The cable routes from the back of the speedometer out the firewall and down to the transmission. It might help the jumping needle if you remove the inner cable and lube it with a light grease. All you have to do is unscrew the cable housing from the back of the speedometer and pull the inner cable out, lube and reinstall. Jim __________________ 1971 Shortbox step side 4x4, 350 sbc, 3:07 rear end 1965 Impala SS 400 sbc, Muncie rock crusher 1966 Impala SS 396 bbc, TH 400 1969 El Camino, 350 sbc, TH 350 1971 Snowplow built on a Blazer frame 1972 GMC Short bed, stepside, TH 400, 427 BBC

06-01-2009, 10:01 AM	#3
Stocker 20' Daredevil (Ret) Join Date: May 2003 Location: Jefferson State Posts: 13,722	Re: Help with speedo ^^ I agree. I thought I pulled mine out from the bottom (transmission) end, but it's been so long ago, I may be wrong about that. Once you get it out, clean it up the best you can. I lubed mine with a lightweight white lithium grease, but I understand graphite lube is better, especially in colder climates. __________________ - Mike - 1972 K20 LWB 350/350/205 RIP El Jay

06-01-2009, 10:36 AM	#4
LockDoc The Older Generation Join Date: Aug 2006 Location: Montezuma, Iowa Posts: 25,774	Re: Help with speedo - I just re-lubed the one in the White Truck. I didn't unscrew it at the bottom. just unscrew the housing from the speedo, work it around the wires and stuff until you can pull it below the dash and pull out the cable. Pull slowly and don't force it or you will ruin the cable. If you feel a lot of resistance, spray some solvent/cleaner down the housing and work the cable back and forth until it loosens up enough to pull it out. Wash the cable off with thinner or solvent of some kind, let it dry and lube it with a light oil. When you insert the cable back into the housing twist it as you push it the last little bit to make sure it seats into the transmission speedometer gear.... LockDoc __________________ Leon Locksmith, Specializing In Antique Trucks, Automobiles, & Motorcycles (My Dually Pickup Project Thread) http://67-72chevytrucks.com/vboard/s...d.php?t=829820 - Last edited by LockDoc; 06-01-2009 at 10:37 AM.

06-01-2009, 11:17 AM	#5
cdowns Senior Member Join Date: Jan 2003 Location: daytonabeach Posts: 22,956	Re: Help with speedo auto parts stores have speedo cable lube//graphite based it polishes the inside of the cable housing with use doesn't harden up and gives a longer life to cable __________________ 71c-10 350/2004r/4:11 lowered3/4 longbed/dead by hurricane MEANING OF DEATH::::: SOMEBODY ELSE GETS YOUR STUFF DONT BELIEVE EVERYTHING YOU THINK TAKE MY ADVISE;I DON'T USE IT ANYWAY

06-01-2009, 11:42 AM	#7
msgross Registered User Join Date: Jul 2006 Location: Central PA Posts: 12,201	Re: Help with speedo good advice guys.. thanks. __________________ The Garage: 1968 K-10 SWB - "Project Money Pit" 1996 Z-71 - "huntin rig" 1969 C-10 LWB (SOLD) "Project flip that truck or else" 1993 Passport, F@rd 1-ton (SOLD)"Project Cousin Eddie" My Garage Build "The 1,000 footer"



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