1980 Speedometer Cable replacement
- Thread starter pbronson
- Start date
D
Dave L.
Guest
I did this job several years ago. It's really tight up under the dash. I removed the drivers seat to make it easier on my back. I first removed the LH lower AC duct. You have to bend it a little and then it will slide out. Then removed the bezel holding the lens in place. Next,I removed the cluster,pulling it forward enough to access the cable. It is held on to the speedo with a spring clip. Take note of how the cable is routed under the hood before pulling the cable through the firewall and down to trans. Reverse procedure to install. It takes a while but this job isn't that hard. You can still get a new a cable at your local GM dealer. Let me know if your car is 4 spd or auto,and if you have cruise control. I'll give you the part number you should ask for.
Welcome to the CAC!
happy motoring...Dave
Welcome to the CAC!
happy motoring...Dave
First, welcome to the CAC! 
Second, does your car have cruise control? The transducer might also be the culprit. Either way, you will have 2 cables if you have cruise, one if you don't.
The worst part is getting the cable end off the back of the speedo. Just very tight working quarters. You have to push on the spring clip as you pull on the cable housing. Kind of tricky. It just pushes back on to re-install.
My former '81 was making noise, and the lower cable (car had cruise control) had been replaced. I replaced the upper cable, and it was noise free- for about two miles. The transducer was bad- it's about $90. Replacing it wasn't too terrible, but it's another "tight working quarters" job.
Rich
Second, does your car have cruise control? The transducer might also be the culprit. Either way, you will have 2 cables if you have cruise, one if you don't.
The worst part is getting the cable end off the back of the speedo. Just very tight working quarters. You have to push on the spring clip as you pull on the cable housing. Kind of tricky. It just pushes back on to re-install.
My former '81 was making noise, and the lower cable (car had cruise control) had been replaced. I replaced the upper cable, and it was noise free- for about two miles. The transducer was bad- it's about $90. Replacing it wasn't too terrible, but it's another "tight working quarters" job.
Rich
- Thread starter
- #4
D
Dave L.
Guest
Do you want to eliminate the cruise and use a one piece cable?
Dave
Dave
- Moderator
- #6
bill81vette
Moderator
Dave L. said:
I'm wondering if this is the reason mine is like this...:confused
D
Dave L.
Guest
Probably is Bill. It was (is) common practice to eliminate the transducer with a one piece cable not only on Corvette but other GM vehicles in that era with a faulty expensive$$ transducer.bill81vette said:
ratflinger
Well-known member
Yes, but. A working cruise control sure makes a long drive less stressfull
- Thread starter
- #9
NavyDavy
New member
I am in the middle of replacing the dash pad on my 1979 C3. It is an automatic with cruise which does not work and the speedometer gets squirrely at 90mph.
I am considering replacing the upper cable before I put the new dash pad back on.
Where exactly is the transducer located, I have not looked for that yet? I may replace that too.
Can't hurt replacing everything I can while the dash pad is off.
Just rebuilt the guage console and put in a working quartz clock, new light bulbs, Air Vent outlets and gauge cluster lens.
Thanks.
I am considering replacing the upper cable before I put the new dash pad back on.
Where exactly is the transducer located, I have not looked for that yet? I may replace that too.
Can't hurt replacing everything I can while the dash pad is off.
Just rebuilt the guage console and put in a working quartz clock, new light bulbs, Air Vent outlets and gauge cluster lens.
Thanks.
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- 1959 black 270hp (9/2/69) 1981 Beige L81(10/20/80)
Welcome to the Corvette Action Center
This is an old thread but still some good info. The transducer is mounted to the driver's side inner front fender panel just below the brake master cylinder. Look down between the master cylinder and the windshield washer reservoir and you will see it smiling back at you. Notice I said you can see it. I didn't say it would be easy to get out of there. With your instrument panel all apart this would sure be the right time to replace that upper cable. 1977 through 1982 use the same upper cable and casing.
It could be that your cables just need cleaned and lubed. Pull the cable out of the casing and clean off the old lube which may be hard and causing interferrence with a smooth rotation of the shaft. Wash out the inside of the casing with solvent and blow out with compressed air then lube the shaft and reinstall. If you don't find any kinks or damage that should restore a smooth operating speedo needle.
As for the cruise not working, my experience with the several '70s and '80s GM cars I've had is failure of the CC switch in the turn signal lever. Although a lot of transducers in this time period did fail, I've never had to replace one. I'd suggest following the troubleshooting proceedure in the factory service manual to determine just where the problem is. You might save money and bandaids.
Your gauge cluster looks great. One trick I have used to restore that dull chrome (never was very shiney) highlight on the edge of the bezel is to go to a Hobby Lobby type of store and get a paint pen or paint stick in a bright silver. It's easy to apply and makes a lot of difference in the finished detail. I have bought these cluster bezels new in original GM boxes and the accent stripe was messed up. This stuff was very thin.
It looks like you have a real nice car.
Tom
This is an old thread but still some good info. The transducer is mounted to the driver's side inner front fender panel just below the brake master cylinder. Look down between the master cylinder and the windshield washer reservoir and you will see it smiling back at you. Notice I said you can see it. I didn't say it would be easy to get out of there. With your instrument panel all apart this would sure be the right time to replace that upper cable. 1977 through 1982 use the same upper cable and casing.
It could be that your cables just need cleaned and lubed. Pull the cable out of the casing and clean off the old lube which may be hard and causing interferrence with a smooth rotation of the shaft. Wash out the inside of the casing with solvent and blow out with compressed air then lube the shaft and reinstall. If you don't find any kinks or damage that should restore a smooth operating speedo needle.
As for the cruise not working, my experience with the several '70s and '80s GM cars I've had is failure of the CC switch in the turn signal lever. Although a lot of transducers in this time period did fail, I've never had to replace one. I'd suggest following the troubleshooting proceedure in the factory service manual to determine just where the problem is. You might save money and bandaids.
Your gauge cluster looks great. One trick I have used to restore that dull chrome (never was very shiney) highlight on the edge of the bezel is to go to a Hobby Lobby type of store and get a paint pen or paint stick in a bright silver. It's easy to apply and makes a lot of difference in the finished detail. I have bought these cluster bezels new in original GM boxes and the accent stripe was messed up. This stuff was very thin.
It looks like you have a real nice car.
Tom
- Moderator
- #12
bill81vette
Moderator
Welcome to CAC!!!
Looks like you are having some fun!!!!!
Good luck with the rebuild!!!!!
Looks like you are having some fun!!!!!
Good luck with the rebuild!!!!!
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