Parts for Caterpillar 3406 - Sensors & Switches Section Loading... 1 Speed Sensor for Caterpillar 3406 and 3408 Engines Magnetic Pick up Price: $ 201.18 Qty: ^ Details Availability Out of stock 2 Speed Sensor for Caterpillar 3406, 3408 and 3412 engines Magnetic Pick up, 3-pin Connector type. Price: $ 114.21 Qty: ^ Details In Stock Add to Cart