speedo help
Thread Starter
Burning Brakes
Joined: Feb 2006
Posts: 841
Likes: 0
From: High Desert California
speedo help
The speedometer on my 81 is very erratic. When driving, it'll suddenly jump and read accurately but will sometimes jump up and down especially when the car is nearing a stop. I was told that there are 2 cables, one for the cruise control. I never used the cruise and doubt if it even works. Does this mean I have a bad cable and if so, which one? Are the 2 cables in some way connected? Can I disconnect one just so I can have my sppedo back? Thanks in advance for your help.
BTW, part # will help as well.
BTW, part # will help as well.
Le Mans Master
Joined: Dec 2006
Posts: 8,837
Likes: 1,027
There is a cable from the tranny to the cruise transducer, then a cable from that to the speedo. The three are essentially connected in series. When the transducer ages and gets gummed up, it tends to take out the lower cable. Non-cruise cars have a longer cable that goes direct.
Take it to a speedo shop. That's all they do, and usually about 150.00.
If you want to takle it yourself, pull out and grease both cables.(They use a red grease). Try turning the transducer by hand. If everything checks out okay, it's the head. Then you are going to the speedo shop anyhow.
Take it to a speedo shop. That's all they do, and usually about 150.00.
If you want to takle it yourself, pull out and grease both cables.(They use a red grease). Try turning the transducer by hand. If everything checks out okay, it's the head. Then you are going to the speedo shop anyhow.
I noticed you're from CA, do you know of any such shops?
Drifting
Joined: Jan 2004
Posts: 1,991
Likes: 3
From: Piscataway NJ
My transducer was loaded with carbon it would barely turn. I took it apart and cleaned it out lube it up its ok. Check the cables too. But my77 had been sitting for 12 years before I got it so that may have played apart in my problem.
Advanced
Joined: Apr 2006
Posts: 87
Likes: 0
From: Finly IN
Speedometer Gear
There is also a plastic speedometer that will give the same indications.
The cost of a replacement gear is ~14.00 less shipping.
I had same indications and found the plastic drive gear was damaged and burred up. It takes longer to jack the car up than to replace the gear. Lubing the cables will help a lot as well.
If you send me a PM or email I will send you a drawing showing the location and gearing.
The cost of a replacement gear is ~14.00 less shipping.
I had same indications and found the plastic drive gear was damaged and burred up. It takes longer to jack the car up than to replace the gear. Lubing the cables will help a lot as well.
If you send me a PM or email I will send you a drawing showing the location and gearing.
Le Mans Master
Joined: Dec 2006
Posts: 8,837
Likes: 1,027
