Oil seals and grease seals keep lubricants in contact with moving parts and keep water, dirt and dust from contacting moving parts. Grease seals typically service rotary parts and bearings, like the wheel grease seals on most any vehicle or the trailer grease seal that keeps lubricant packed in trailer wheels. These seals also service industrial equipment.

The seal types of grease seals or oil seals vary by number of lips, usually one to four. There are also U-ring , V-ring, labyrinth seals and bearing isolators. Often times a spring helps keep pressure on the seal. The direction and orientation of the seal is important for proper operation and comes in several configurations:

1. Rod or shaft seals (radial) slip over a shaft and fit into the housing bore.

2. Piston seals (radial) slip over the shaft and but up to the housing bore.

3. V-ring grease seals are external lip seals.

Action Steps
The best contacts and resources to help you get it done

Buy auto grease seals, RV grease seals and trailer grease seals

Various types of vehicles require different sizes and grades of oil and grease seals. Shop grease seal distributors that carry a wide selection of products for your type of vehicle. It is especially important to maintain trailer grease seals.

I recommend: Trailer Parts Superstore not only services conventional trailers, but boat trailers and RVs as well. Since there are a wide variety of auto grease seals, heading to the auto parts store is not a bad idea if it's time to replace a CV joint cover or other car grease seal. However, there are also online sources, like CarParts.com where you can search by make, model and year.

Locate metric grease seals and metric oil seals

Many suppliers sell both metric and standard English sizes for their seal products; but if you're hunting for metric sizes, make sure to shop grease seal suppliers that have more than a limited supply of metric products.

I recommend: MSP Seals, Inc. carries both metric and inch sizes of radial lip seals and oil seals, in addition to other seals, such as those for hydraulic cylinders. Allied Metrics Fasteners and Seals, Inc. carries metric sizes of nearly all types of seals, nicely categorized. Definitely check out their website.

Purchase the best industrial and labyrinth oil seals

Industrial grease and oil seals service a wider range of applications and have higher tolerances than general wheel bearing grease seals. Find manufacturers that specifically service manufacturing and heavy industrial processing.

I recommend: AFM carries oil seals, including piston and rod seals. They listen to their customers and take into account the speed, temperature and motion (rotational or reciprocating) of your application to help you choose the seal that will perform best for you. EPM is another good source. Among their large stock are high temperature seals and specialty seals, as well as information on installing grease seals.

Tips & Tactics

Helpful advice for making the most of this Guide

• •  Labyrinth seals serve many purposes, but keep in mind that they usually only perform well in high speed machinery.