Oil Seal
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National Oil Seal

Part No. 3909 Warranty Details  
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Designed to provide enhanced endurance and maximum contamination exclusion while ensuring proper fit, form and function.
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Lip Material:Fluoroelastomers

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2 Questions | 2 Answers
Displaying questions 1-2
  • Q:

    I have installed many RMS's. I read somewhere that this brand (National) was supposed to be installed dry, as in no oil or grease on the inside lip of the seal. Is this true?
    Asked on 7/26/2015 by Hugger Orange from Louisiana

    1 answer



      Good question, Hugger Orange! But, it's not true. The National oil seal should be prelubricated with grease or oil to reduce sliding friction of contact surfaces. An oil seal, often called a grease or dirt seal, is a type of seal utilized to retain grease in a case or housing. Oil seals close spaces between stationary and moving components in mechanical equipment, helping prevent lubricant escape.

      Answered on 7/27/2015 by Solomon
  • Q:

    Is the gasket 3909 made of Teflon or rubber?
    Asked on 6/24/2014 by Rob from Delray Beach, Florida

    1 answer



      Hi Rob, glad to asssist you! This gasket is made of Fluro-Elastomer material.

      Answered on 6/25/2014 by Vincent from AAP
Displaying questions 1-2

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