C3 speedometer cable
- Thread starter Rossco
- Start date
Chuffer
CCCUK Member
Firstly , does your C3 have cruise control ? If so there are two cables , a longer one from the auto trans to the cruise module and a shorter one from the module through the bulk head to the speedometer .
Hmmm, there are cruise controls on a stalk, but I hadn't assumed that the cruise system was fitted, and I failed to ask on purches of the car( few weeks ago). The cable is not one piece though, there is a connector a short distance from the trans, which I split to have a look, I can see where the cable end and square keyway is worn.
Forrest Gump
CCCUK regional rep
1977 was the first year of cruise control (unless it's been retrofitted to your car somehow)
Chuffer
CCCUK Member
Not sure if a 1974 is the same as a 3 speed 1980 with cruise but have a look on drivers side engine bay inner wing area just behind and below the brake servo unit . The Cruise control unit is located down there . The incoming cable from the trans and the outgoing shorter cable to the speedo are detachable via knurled collars . What is your problem ? Speedo not working ? It is possible that your Cruise Control transducer has been bypassed if you have a two piece cable but normally this is achieved by fitting a much longer one piece cable for a non cruise fitted C3 which I did as my Cruise Control was disabled due to various mods carried out before I bought the car .
I'm away at the moment, but will check the set up when I get back. My speedo flicks up and down, almost pulsing. So there is no possibility of working out what speed you doing. I just split the cable at the knurled connection to see what state the cable was in. What cable did you order for your C3, the single non cruise option??
johng
CCCUK Member
Rockauto have a range of lengths available
1974 CHEVROLET CORVETTE 5.7L 350cid V8 Speedometer Cable | Shop Now at RockAuto
1974 CHEVROLET CORVETTE 5.7L 350cid V8 Speedometer Cable | Shop Now at RockAuto
Roscobbc
Moderator
This may have been mentioned previously but a 'flicking' speedo needle is often the result of an insufficiently lubricated inner cable and/or out cable routed too tightly under the dashboard etc..........the inner cable will effectively 'wind-up' and release continually, perhaps causing the 'flicking'?
Chuffer
CCCUK Member
I ordered my cable from Corvette Kingdom . As Ross said , it could be a tightly routed or non lubricated cable . If the end of the cable is worn it may well be slipping in the square hole it locates in . It could also be the damper in the speedo failed which is designed to stop the needle bouncing . Eliminate cable issues first as that is a cheaper fix as speedometers are expensive and can be hard to come by .
If it’s like the 1980 model, check the driver’s side inner wing near the brake servo for the cruise control unit. Cables from the trans and speedo connect there. If the speedo isn’t working, it might’ve been bypassed with a one-piece cable if cruise control was disabled.