Wiper Arm & Blade CAT312 CAT320

Compatible with the following equipment:

Part Number: 

An excavator wiper arm and blade is the windscreen wiper assembly on the operator’s cab. It sweeps rain, mud, dust and spray off the front glass so the operator can see the bucket, the trench and people around the machine.

The two parts
• Wiper arm: the metal arm, usually spring-loaded, that bolts onto the wiper motor’s drive shaft (spindle). It holds the blade against the glass with steady pressure and carries it through its sweep. Arms attach with a splined or tapered spindle head held by a nut, and the spring tension sets how hard the blade presses.
• Wiper blade: the rubber wiping element in a frame that clips onto the end of the arm. This is the part that wears out. The rubber hardens, cracks or tears from UV, heat and abrasive dust, and then it smears or leaves streaks.
How excavator wipers differ from car wipers
• Mounting: many excavator cabs have a front window that slides up into the roof. As a result, the wiper is often a single arm, either top-mounted or on a pivot that clears the sliding glass. It is not the twin bottom-mounted setup you see on a car.
• Sweep type: some machines use a standard arc sweep. Others use a pantograph (parallel-link) arm that keeps the blade more upright and clears more of the tall, narrow screen.
• Build: arms and blades are heavier duty, because they deal with constant vibration, mud and high-pressure washing.
• Fitment: parts are often model-specific. Arm length, spindle spline count and taper, and blade length and connector type all vary between brands and models, such as Kobelco, Komatsu, Cat, Hitachi, Volvo and Doosan. Suppliers usually list them by OEM part number. For example, Kobelco uses numbers like YN53C01003F1 for an arm-and-blade set.
Related parts in the system
The wiper motor, the linkage (on pantograph types), the washer bottle and pump, the washer jet or nozzle, and the wiper switch in the cab.