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25% Off Online Orders of Select Hard Parts. Enter Promo Code MMJ25 in Cart.

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Receive Up To 25% Off Your Online Purchase Of Select Parts And Accessories
Use promotional code MMJ25 at checkout to receive 25% off the following categories: Select Brake Parts, Select Hi-Performance and Truck Accessories, Batteries, Water Pumps, Belts, A/C Parts, Starters, Alternators, Fuel Pumps, Radiators, Radiator Fans, Thermostats, Caps & Clamps, Clutches, Spark Plugs, Plug Wires, Chassis, CV Axles, Batteries, Battery Chargers & Booster Cables, OE Locks, Rack & Pinons, Window Motors, RainX Wipers, Appearance Chemicals, Car Wash Accessories, Floor Mats, Lift Equipment, Hand Tools, Travel Accessories, Outdoor Lifestyle, Towing, Car Covers, Seat Covers, Wheel Covers, Body Repair, Collectibles and Apparel.

Use promotional code MMJ20 at checkout to receive 20% off the following categories: Ignition, Air Filters, Oil Filters, Bearings & Seals and Engine Parts.

Offers not valid in combination with any other discounts, promotions or items already on sale. Not valid on gift cards, special orders, installed merchandise, commercial or fleet purchases. Those products that are included in these offers will be displayed in product search results and product detail pages. Excludes the following brands: Champion, Powerstop, Razor, Traxxas, Superchips, Hypertech, Edge, Bully Dog, Diablo, Edelbrock, Holley, NOS, Proform, Specialty Auto, Autometer, Accel, K&N, Kenwood, Pioneer, Sony, Thule, Thule Karrite, JVC, Flowmaster, Hurst, B&M, MSD, Moog, Wagner, Philips and BBK Performance. Valid online until 11:59 PM EST on 9/24/17.

Use promotional code SHOCKS25 at checkout to receive 25% Off DIY Shocks & Struts

Receive 25% Off Wagner branded brake parts with your online purchase. Use promotional code: WAGNER25.

Receive 10% Off Select Champion, MOOG and FelPro branded products with your online purchase. Use promotional codes: CHAMP10, MOOG10 and/or FELPRO10.

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Oil Seals


Oil Seals

Oil seals are devices that hold or separate fluids of various types to ensure larger assemblies (transmissions, differentials, engines, etc.) continue to function where lubrication or fluid separation are required to reduce friction and wear.

What is an oil seal and how does it work

How Does It Work?

  • Small membrane of oil (viscous fluid) separates the rubber from the metal or non rubber component by way of a hydraulic pressure barrier of oil created through motion and geometric down force of the seal head.

How Is it Made?

  • Metal stampings are pressed out, rubber is mixed to suit conditions, both parts are then compressed together and bonded in a larger press to form a seal.

Why Does it Fail?

  • Seals can dry out if not used for a period of time.
  • Severe driving conditions, including cold, can crack seals.
  • Drivetrain damage such as a damaged driveshaft or drive axles can cause excess vibration and seal wear.
  • Aging seals and bearings can pull away from the surface they mate with and leave too much space, allowing oil to escape.
  • Improper maintenance.

What are the Symptoms of Failure?

  • Fluid deposits.
  • Fluid leaks.
  • Noise due to friction related to lack of lubrication.

What are the Implications of Failure?

  • Catastrophic failure can mean engine, transmission, or differential damage.
  • Very minor implications can include small leaks.
  • Shorten assemble life.
  • Depending on the severity of the failure, repairs can be costly.

How Difficult is the Install?

Difficulty Rating:


  • Installation difficulty can vary from simple to complicated depending on where the oil seal needs to be replaced.

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