Modified Mustangs & Fords Homepage

P147905 Image Large

Prev Next
Speedometers are easy to understand. The speedometer head (A) is tied to the spinning cable. The spinning speedometer head turns a magnet (B) inside the needle drum (C). When the magnet spins around, the magnetic attraction pulls the needle drum clockwise (from driver’s position) from “0” upward. The speedometer head also drives two worm gears (D) that turn the odometer elements (E). Speedometer heads do wear out, causing a clicking sound and a bouncing needle. Regular maintenance prevents this. Lubricate the speedometer head and the worm gears for best results.
Instrument Panel Function & Electrical Basics

 Speedometers are easy to understand. The speedometer head (A) is tied to the spinning cable. The spinning speedometer head turns a magnet (B) inside the needle drum (C). When the magnet spins around, the magnetic attraction pulls the needle drum clockwise (from driver’s position) from “0” upward. The speedometer head also drives two worm gears (D) that turn the odometer elements (E). Speedometer heads do wear out, causing a clicking sound and a bouncing needle. Regular maintenance prevents this. Lubricate the speedometer head and the worm gears for best results.  View Related Article

 

Get Adobe Flash player

Car Research Guide