Did you check to make sure the speedo cable isn't broken. Disconnect both ends and twist the inner cable and look at the other end to see if it moves. It should move easily.
You can take a short cut and just disconnect the speedo end and have someone rotate the left wheel and you should be able to see the inner cable rotate.
The one on the left wheel is attached to the grease/bearing cover with a c-clip. Remove the c-clip then take the cover off (so you can reattach it) and it will just pull out of the hole on the axle side. The grease/bearing cover actually turns the cable as the end of the cable is square to fit in the cover hole that is square. Sometimes the hole will round out and the cable won't rotate with the cover.
i own a 1973 super beetle and when i bought it i had the same problem. we fixed it by replacing the speedometer cable on it. the cable runs from the front, driver-side tire and goes in to the back of the gauge it gets a little tough unless you have tiny hands but that fixed it for me.
decode vin 1973 Volkswagen beetle
1973 standard and super beetle
trailer
How I have to do for replace a little bulb on the ODO speedometer cable on 1973 Super Beetle ?
10w30 same as a 73 standard beetle
1600 cc.
1600 cc.
The biggest difference is the 74 has energy absorbing bumpers that the 73 is lacking.
thesamba.com has everything
1973 super beetle comes with 1600 cc motor.
P165/80R15 is the standard size.