DRIVE GP-MULCHING HEAD 4821472 - Caterpillar

Engine hood and engine hood parts can be hot while engine is running or immediately after engine shutdown. Hot parts or hot components can cause burns or personal injury. Do not allow these parts to contact your skin, when engine is running or immediately after engine shutdown. Use protective clothing or protective equipment to protect your skin.
If the engine is running or the key is in the ON position the ARD plug will continue to fire. Turn the key to the OFF position before servicing the ARD plug.
Illustration 1 g02113380
(1) Wiring harness
(2) Spark plug
Position the machine on a level surface and lower the bucket to the ground.
Move the hydraulic lockout control to the LOCKED position. Stop the engine.
Allow the exhaust system to cool before performing this procedure.
Unlatch the engine hood and raise the engine hood.
Remove any dirt or debris from the area around the spark plug.
Remove wire harness (1) from spark plug (2).
Use a deep well socket and a breaker bar to loosen the spark plug. If necessary, see your Caterpillar dealer for the part number of the socket. After the spark plug has been loosened, use the socket to remove the spark plug by hand in order to detect problems with the threads.
After removing spark plug, clean the ground probe inside the ARD combustion head by running a Plug Bore Brush through the hole in the ARD combustion head. Run the brush through the hole several times.
Carefully clean the spark plug using a nonmetallic cleaning pad. If the probe appears to be bent, replace the spark plug. Otherwise, install the original spark plug. Note: The spark plug may be damaged if the spark plug is dropped. Do not install a spark plug that has been dropped.
Do not overtighten the spark plug. The shell can be cracked and the gasket can be deformed. The metal can deform and the gasket can be damaged. The shell can be stretched. This will loosen the seal that is between the shell and the insulator, allowing combustion pressure to blow past the seal. Serious damage to the engine can occur.Use the proper torque.
Install the spark plug by hand until the spark plug contacts the ARD. Tighten the spark plug to a torque of 43.4 N m (32 lb ft) to 51.5 N m (38 lb ft).
Connect the wiring harness.
Close the engine hood and latch the engine hood.