OIL SEAL INSTALLATION

[GENE DERRINGER]

This is probably a dumb question to most, but I have found conflicting opinions on which side of an oil seal faces the oil? Some say the lip, others say the spring side faces the oil. Please give me your opinion and logic. Thanks.

 

[Mike M]

There are several styles of seals. The most common is the type with a lip and a tension spring on it. On this style the lip with the tension spring goes towards the oil you are trying to keep from leaking out.

 

[Steve@Advance]

With any lip type seal, the cup side, the side with the garter spring, always goes toward the liquid you are trying to contain.

Some seals are double lip, with a small lip on the flat side. This goes to the outside as a contaminate guard.

Some extreme applications, like under water, will use back to back seals. In this situation, the seal lips face away from each other.

 

[Rkh]

An old time mechanic told me to add an o ring next to the seal as close to the diameter of the shaft (if you have room) to help prevent leakage.

 

[gab]

Spring side towards oil usually, something like my Wheel Horse tiller tine shaft has one seal spring toward grease next seal spring out to keep dirt out.

 

[GENE DERRINGER]

Many thanks to all of the replies - I really appreciate your advice.

 

[Bob]

Look at Page 9 in the SKF study guide linked below. (.pdf)
SKF study guide

 

[FBH44]

I install seals with the U facing the oil / grease, so the U fills up with oil / grease. I also finally figured out to NOT tap or pound the seal, noawadays they are flimsy metsl. I use some sort of home-made sleeve of the correct diamter to fit around the shaft and then I tap on the sleeve. For example, I found that a 3-inch PVC piece of pipe or bushing is the perfect sleeve to tap the rear brake seals in on a H Farmall. Perfect.