The VDO fuel gauge in my 1966 VW Bug is the original fuel gauge and still worked perfectly until the cable inside broke. I took a look around for replacement fuel gauge cables but there were none to be found. A few of the online shops had the entire fuel gauge and cable combination, but nobody carried just the cable. The replacement gauges were rather expensive compared to what a cable should cost and the new gauges say Gasolina instead of Tank. So I was off to investigate a fix.
First I looked to see where the problem occured with the cable. Turns out that the cable has a small ball on the end of a wire and that ball broke off the end of the cable. If I had been able to just reattach the ball on the end it would have been a very quick fix but with the cable being old and broken once, I didn't think that was a good plan. So I pulled the fuel gauge out of the beetle and started to disassemble it.
To disassemble the volkswagen gauge was very easy. First the chrome trim must be carefully removed from the gauge. I did this with a small screw driver. When the chrome trim is removed, the part of the VDO fuel gauge that says Tank is loose so I think that if you wanted you could put that part on a new gauge and be done.
There are two small screws on the face of the VW gauge that DO NOT need to be removed. Next the two small tabs on the back of the gauge housing must be straightened. Once they are straight you can push the inside of the gauge out of the housing. You will find that the cable on this end is the same as the other end.
To fix the bug gauge cable, I went to a bike shop and purchased some brake tubing and cable to use. The new brake tubing and cable have low friction so it shouldn't affect the ability of the gauge. Measure out the right amount of tubing and cut it and do the same with the cable but leave a little extra to work with. The new cable will need to be have an end attached. I used the smallest slip shot sinker (fishing weigth that pinches onto the line) I could find. I attached the sinker and tested its size on the gauge and it was good so I removed it and added some epoxy so that I wouldn't ever slide off (I hope). You might also be able to solder it but I didn't want to deal with the lead so I used epoxy. Cut any excess cable off to make sure it doesn't rub the gauge housing.
Next fish the cable through the gauge housing and then through the new brake tubing. At the other end you will need to attach it to the volkswagen fuel sender. Instead of doing the slip shot sinker again I just wrapped it around the fuel sender attached a crimp on brake end cap I got at the bike shop. It was much quicker to deal with (and it was cold out).
Next you have to recalibrate the gauge. If your cable is the identical length no need to worry but I wasn't that lucky. I filled the bug's tank, reset the dial to full and then turned it down slightly so that I would think the tank had less fuel than it did. Then I drove it around (keeping track of my miles) until the tank was low and then readjusted the calibration.
For less than $10 of parts I have a working original VDO fuel gauge in my VW Bug.