How are the seals supposed to be installed, flat side out or flat side toward bearing? I've seen it both ways.

How are the seals supposed to be installed, flat side out or flat side toward bearing? I've seen it both ways.

 

Here's a third way

 

The seals I put in when I did my bearings didn't really have a flat side. On one side was the groove that has the spring in it. The other side had a ridge or lip or flap. Because of this flap it was possible to put the seal in only one way. When assembled this lip rode along the CV joint (inner bearing) or rotor (outer bearing).

I put the "flat" side in, and the "spring/flap" side out toward CV/hub.

I put the "flat" side in, and the "spring/flap" side out toward CV/hub.

 

That will keep water / dirt out if it is at higher pressure than the housing. It won't keep the grease in. The spring should not be exposed to the outside environment. All of the wheel bearing seals I have seen have the extra flap mentioned previously also. The spring goes toward the grease, the extra lip helps keep out dirt.

Well you learn something new everyday...

 

I've only done one axle/bearing job. Spring out seemed like the only right way to do it.

 

I haven't had any grease leak in over 30K miles.