Oil seals

OIL SEALS

Always renew oil seals which have been removed from their working location (whether as an individual component or as part of an assembly).

• Carefully examine seal before fitting to ensure that it is clean and undamaged.
• Ensure the surface on which the new seal is to run is free of burrs or scratches. Renew the component if the original sealing surface cannot be completely restored.
• Protect the seal from any surface which it has to pass when being fitted. Use a protective sleeve or tape to cover the relevant surface.
• Certain oil seals are coated with a protective wax and must be fitted dry unless stated otherwise. Where an oil seal needs to be lubricated prior to fitment, lubricate the sealing lips with a recommended lubricant before use to prevent damage during initial use. On dual lipped seals, smear the area between the lips with grease.
• If a seal spring is provided, ensure that it is fitted correctly.
• Place lip of seal towards fluid to be sealed and slide into position on shaft. Use fitting sleeve where possible to protect sealing lip from damage by sharp corners, threads or splines. If a fitting sleeve is not available, use plastic tube or tape to prevent damage to the sealing lip.

• Grease outside diameter of seal, place square to housing recess and press into position using great care, and if possible a ’bell piece’ to ensure that seal is not tilted. Never let weight of unsupported shaft rest in seal.

NOTE: In some cases it may be preferable to fit seal to housing before fitting to shaft.

• Use the recommended service tool to fit an oil seal. If the correct service tool is not available, use a suitable tube approximately 0.4 mm (0.015 in.) smaller than the outside diameter of the seal. Use an hammer VERY GENTLY on drift if a suitable press is not available.
• Press or drift the seal in to the depth of its housing with the sealing lip facing the lubricant to be retained if the housing is shouldered, or flush with the face of the housing where no shoulder is provided. Ensure that the seal does not enter the housing in a tilted position.

NOTE: Most cases of failure or leakage of oil seals are due to poor fitting, which can result in damage to both seals and sealing surfaces. NEVER use a seal which has been improperly stored or handled, such as hung on a hook or nail.