Speedometer issues with my '81
Thread Starter
Burning Brakes
Joined: Jun 2000
Posts: 951
Likes: 0
From: NW Burbs IL
Speedometer issues with my '81
I just read through a speedometer thread for a '69, but I have to think that there are some pretty significant changes between '69 and my '81.
The last month my speedo has been jumping a little. The last week or so, it was jumping wildly until about 15 or 20 MPH when it would level out. Today, I drive off for lunch, look down and realize that I was going nowhere fast.
I don't think that a cop would have appreciated the humor of me saying "Oh, about 0 MPH" if I got pulled over and asked how fast I was going. The speedo, the odo, and the trip all are not working.
So, the cable is the usual culprit from what I've heard, but which cable and how hard is it to change. I have cruise control, so is one more likely to get chewed up as opposed to the other? Is one easier to check than the other? I've never really messed with the speedometer, cruize, or anything and have mild mechanical skills. I can do quite a few things on my car, but the harder projects I just don't bother with. Is this fix something I should be able to do, or is it more difficult?
Also, if it's not the cable, what is the next most likely problem?
Thanks to all in advance for your help!!
The last month my speedo has been jumping a little. The last week or so, it was jumping wildly until about 15 or 20 MPH when it would level out. Today, I drive off for lunch, look down and realize that I was going nowhere fast.
I don't think that a cop would have appreciated the humor of me saying "Oh, about 0 MPH" if I got pulled over and asked how fast I was going. The speedo, the odo, and the trip all are not working.So, the cable is the usual culprit from what I've heard, but which cable and how hard is it to change. I have cruise control, so is one more likely to get chewed up as opposed to the other? Is one easier to check than the other? I've never really messed with the speedometer, cruize, or anything and have mild mechanical skills. I can do quite a few things on my car, but the harder projects I just don't bother with. Is this fix something I should be able to do, or is it more difficult?
Also, if it's not the cable, what is the next most likely problem?
Thanks to all in advance for your help!!
Safety Car
Joined: Nov 2004
Posts: 4,359
Likes: 57
From: Mundelein Illinois
In most cases it is the cable going from the cruise unit to the trans. It usually breaks by the trans. It could also be the cable that goes from the cruise to the dash or both. Check them out.
To change either is not big deal. Just determine what cable you need an order a new one
To change either is not big deal. Just determine what cable you need an order a new one
Racer
Joined: Nov 2003
Posts: 386
Likes: 1
From: Grafton WV
Check the Cruise Control Transducer box if it is screwed up you will just mess up another cable. I bypassed the Cruise box and went directly from the Transmission to the Speedo. Problem with snapping cables fixed but no cruise. But who the Hell uses the cruise anyhow.
Le Mans Master
Joined: Jan 2006
Posts: 9,192
Likes: 27
From: Boca Raton Florida
Yea, its easy to check one cable as the other. My speedo jumped all over the place too. I think I found the culprit, the cruize module was full of grease and pretty much fornicated inside. I am waiting on a new unit (rebuilt). Disconnect the tranny cable at both ends and see if it broke, replace if necessary and lube it well before reinstalling.
Melting Slicks
Joined: Nov 2000
Posts: 2,507
Likes: 114
From: St. Louis Mo
Yea, its easy to check one cable as the other. My speedo jumped all over the place too. I think I found the culprit, the cruize module was full of grease and pretty much fornicated inside. I am waiting on a new unit (rebuilt). Disconnect the tranny cable at both ends and see if it broke, replace if necessary and lube it well before reinstalling.
Drifting
Joined: May 2006
Posts: 1,480
Likes: 2
From: Circleville Ohio
Vader Vette
I used the cable greaser from cc and it has proved its self to me .I heard the grease goes up the cable so I would start with small pumps (from the grease gun)After you find out the problem.a new cable should not need any lube but if it did . "cable greaser".
Safety Car
Joined: Dec 2004
Posts: 4,071
Likes: 0
From: San Diego CA
Check the Cruise Control Transducer box if it is screwed up you will just mess up another cable. I bypassed the Cruise box and went directly from the Transmission to the Speedo. Problem with snapping cables fixed but no cruise. But who the Hell uses the cruise anyhow.
Uhhh I do. Try driving from San Diego to Tucson and back with no cruise. It kinda sucks.
The way I tested to see which cable broke when mine did this is I took the cable that goes from the speedo to the cruise and spun it with a drill. If the speedometer needle moves, it's either the transducer or the cable from the transducer to the transmission. 95% of the time it's the cable, which is $7 at www.partsamerica.com or your local kragen/schucks/checkers. Make sure to print out the price on their website before you bring it in because in store it's about $17.99 and online it's $7.99 or something like that. Now plug the new cable in to the transducer and give it a spin with the drill or your fingers, if the speedometer moves you just fixed it. If it doesn't make sure the cables are seated in the transducer. I had that problem once. I highly doubt your transducer is bad, by the way. Kind of rare that they break.
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