Seal, which way should it go

[Henri88]

I'm replacing the output seal on the button of my Howse 4' bush cutter. It was leaking and since I just bought it use, I'm questioning if it was install correctly. I'm sure it was at the factory, but it could have been change afterward. Usually to my recollection, when you install a seal, the face of the seal is on the outside, but in this case it is facing inside the gearbox. Anyway, I took some pictures of the way it is set-up but I'm really not sure this is the right way. Please take a look and give me your feedback. The way it is set-up, their is a space between the endcap and the seal. This space was fill with grass and whatever manage to get in there. Suspect that this could have been the reason for the leak. Edit: Forgot to mention, this is a double lip seal.

 

[mikefamig]

Henri:

The side with the lettering is the dry side.

Mike.

 

[whistlepig]

Are you asking which direction the lip of the seal should go?

 

[Henri88]

Henri:

The side with the lettering is the dry side.

Mike.

Mike that's what I thought also. The way it is set-up right now, the lettering would be facing the bearing.

 

[Henri88]

Are you asking which direction the lip of the seal should go?

Yes! Does it look right to you?

 

[whistlepig]

As Mike said. Lip pointing out for grease. Lip pointing in for oil.

 

[BRBurns]

That looks like it could be backwards,but it hard to tell for sure from the pictures. Basically, you want it so if pressure is to increase inside the gear box it pushes the seal towards the shaft.

 

[whistlepig]

Most oil applications are not pressurized. Lip goes in. Most grease applications are pressurized. Lip goes out. Lip in on a grease application and a squirt or two too much with a pressure grease gun will blow the seal.

 

[Henri88]

That looks like it could be backwards,but it hard to tell for sure from the pictures. Basically, you want it so if pressure is to increase inside the gear box it pushes the seal towards the shaft.

In that case, it would be install correctly. Also I forgot to mention but this is a double lip seal. On this pic you can see the small lip turn outside so with any kind of pressure the lip would push again the shaft.

 

[mikefamig]

Most oil applications are not pressurized. Lip goes in. Most grease applications are pressurized. Lip goes out. Lip in on a grease application and a squirt or two too much with a pressure grease gun will blow the seal.

That makes sense, you learn something new every day.

 

[mfreund]

I cannot tell from the pictures, but have always went on the addage lip to the pressure, or what you want to contain.

 

[Chilly807]

Is there a garter spring in the seal? If so, that is definitely on the oil side. A double lip seal is designed so the outer lip keeps contaminants such as sawdust or dirt from getting to the oil sealing lip and damaging it. Generally, any lettering will be on the dry side of the seal as the guys have said.

Sean

 

[whistlepig]

I cannot tell from the pictures, but have always went on the addage lip to the pressure, or what you want to contain.

If a grease bearing is over greased the only place for it to relieve is through the lip in the seal. If lip out the grease can seep through. If lip in it the pressure of the grease will blow out the seal.

 

[Henri88]

Ok, so I took a run to my garage and had a better look at the seal. First, yes there is a spring inside and it is on the inside lip in other word if you are looking at the seal with the # facing you, it would be the second lip inside. That lip is also different than the other one. It is made more like a V shape. The other lip closest to you or I should say closest to the face of the seal with the # is more like a wiper lip and is shape going outside. I took some more pics. So if logic stands, the lip with the spring, shape like a V should be the oil seal and the other lip should be the one stopping the contaminant from going in which mean the seal is wrongly install. Your thoughts please.

 

[whistlepig]

Spring matters not. Lip in for oil. Lip out for grease.

 

[Henri88]

Spring matters not. Lip in for oil. Lip out for grease.

I don't get it. There is no grease and both lip are different. You may be right but I still don't no by your quote which lip is the oil seal.

 

[whistlepig]

We replace bearings on chilled cast iron calender rollers for paper mills and steel mills. These calender rollers weigh 35 tons+. The bearings for these calender rollers are most time grease bearings but sometimes oil bearings. A single spherical bearing for one these rollers costs from $3,000-$4,000. It's lip in for oil and lip out for grease. Regardless of which side the numbers on the seal are.

 

[BRBurns]

The side where you can see the spring defiantly goes towards the oil.

 

[donaldmaciver]

You are correct in what you are saying, this is indeed a double lip type seal, the open side of the seal should face the oil or grease. the other outer lip is to prevent contamination from entering the seal and bearing area.
Before installing the seal I would check the bearing and shaft for any excessive wear that would make the new seal weep oil. Another thing to check here is that the vent/ breather on the housing is clear and that there is no chance that pressure could build up within the housing.
Hope this is of some help

 

[SSdoxie]

The side where you can see the spring defiantly goes towards the oil.

:thumbsup:

Spring side with a lip is fluid retention.