2W6078 Pinion-Drive Fits Caterpillar Models

One New Aftermarket Replacement Drive Pinion for Caterpillar (Cat) Engines and Equipment

This 12-tooth drive pinion (part number 2W6078 / 2W-6078) is a component of Caterpillar vane air starter motors. The drive pinion engages and rotates the engine flywheel ring gear during air starting, transmitting rotational motion from the air starter motor to crank the engine. It is hardened to withstand high-impact engagement loads and features a 6-tooth right-hand helical spline drive shaft interface for positive torque transfer. Used across a wide range of large Cat diesel engines, power units, and off-highway trucks equipped with vane-type air starters.

Specifications

• Teeth: 12
• Drive shaft interface: 6-tooth, right-hand helical spline
• Weight: approximately 1.0 lb
• Dimensions: approximately 2.76 x 2.36 x 1.97 in.
• Application: Caterpillar vane air starter motor

Compatible Models

Caterpillar Engines: 3412, 3412C, 3412D, 3412E, 3508, 3508B, 3508C, 3512, 3512B, 3512C, 3516, 3516B, 3516C, 3606, 3608, 3612, 3616

Caterpillar Off-Highway Trucks: 776C, 776D, 777D, 784B, 784C, 785, 785B, 785C, 785D, 789B, 789C, 793B, 793C

Caterpillar Mining Shovels / Large Equipment: 5230, 5230B

Note: This part fits various Cat machines equipped with vane air starters. Verify air starter configuration before ordering.

Replaces Part Number(s):

2W6078, 2W-6078

New aftermarket replacement part - not remanufactured, not used.