Sealing principle: Since there is an oil film controlled by the oil seal edge between the oil seal and the shaft, the oil film has fluid lubrication characteristics.

794 00055a spark plug. Over time, spark plugs can become fouled with carbon deposits, which can decrease their effectiveness. The 794 00055A spark plug is designed to resist fouling, ensuring that it will continue to provide a consistent spark for optimal engine performance.
Sealing Element
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To do this, turn the engine with a socket on the crankshaft pulley bolt until the rotor arm is pointing to the plug contact of the timing cylinder (usually No. 1, check in the car service manual), and the timing marks on or behind the pulley show exactly top dead centre ( TDC ).

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However, the new variant also comes with less good properties. Namely less flexibility and less resistance during assembly. Most damages therefore occur during the installation of PTFE oil seals.
• Low-friction torque design
Oil leak: the most frequent failure of the oil seal
Oil seals are used in a great many machines.
Similar to the housing surface stop technique, this method uses a stop at the machined housing face to set the seal depth. It is typically used in housings with flat outer surfaces. Verifying the placement through visual inspection or with a feeler gauge ensures placement accuracy.