Trimatic Speedo Drive
Originally submitted by T:
Speedo Drive:The Speedo Driving and Driven Gears can be changed to match tyre size and differential ratio.
Charts for these are available under Holdenpaedia.
The Speedo Cable:
Before unbolting and removing the Speedo cable it is imperative to make a large loop out of the cable. Simply unbolting the cable and pulling it out of the casing will put a kink in the cable, especially in Toranas.
The kink will be more than the plastic Speedo Driving and Driven Gears can turn and they will eventually strip. The only fix is to replace both the Driving and Driven Gears as well as the cable.
A kinked Speedo cable is characterised by the Speedo needle in the Speedometer bouncing up and down as the car moves forward.
The Speedo Driven Gear:
The Speedo Driven Gear is mounted on the end of the Speedo cable.
The Speedo Driving Gear:
The Speedo Driving Gear is mounted on the Tailshaft inside the Rear Housing. Remove the Rear Housing to remove and replace the Driving Gear. A Clip holds the Driving Gear onto the Tailshaft. You compress the Clip's thumtab then slide the driving gear off the Tailshaft. The new Gear is slid on and clips into place.
The Speedo Needle Jumps:
1. Kinked Cable.
2. Stripped Driven Gear (on Cable).
3. Stripped Driving Gear (on Output Shaft).
4. Cable not pushed into the Speedo correctly. It needs to latch or screw into place