Orientation of front wheel bearing seal...C2

[Jim V.]

Pic below shows the FM 7934S seal used on the C2. The rubber seal is offset in the metal housing (not centered) closer to SIDE B as pictured. The rubber seal does NOT have an angled lip...but rather a square face.

Which is the outboard side (grease side) for installation...side A or side B...or does it matter?

Thanks

[Phil P.]

i always put side A towards the bearing *NM*

[Rainer S.]

Re: i always put side A towards the bearing

You have what is known in the automotive/machine building industry what is called a "double lip seal". When you look closer at the seal , you will see two edges, one edge is more pronounced than the other. That edge goes to the outside, the other, minor edge goes toward the inside.
When using the seal for a grease pocket (your application), the major edge should point out,to keep dirt out. When using the same seal on an oil application, such a trans gearbox, that edge goes toward the inside, keeping oil in. The other, minor edge will keep dirt out...
In your case, side A should face out, if the A edge is the more pronounced edge, which I think it is, looking at your photo.

Rainer

[Rainer S.]

Re: i always put side A towards the bearing

One additional point, when talking about oil or grease seal.
When you install the seal, with the A side facing out, be sure you use a sleeve or tube, which has an outside dia slightly smaller (.003" to .005") than the bore dia. That way, the force to press the seal in is exerted on the outside edge of the seal, not where the actual seal is.
When installing seals with the solid casing toward the ouside, it's not so critical, what you use, since the backside of the seal is fairly strong.
Here at Ford, we have a set of special seal installation tools, which utilize a plastic cup, that is "dished" toward the center, avoiding any force on the center of the seal.
You wouldn't believe, how many of our Trades do not know how to install seals correctly, when repairing our machines.

Rainer

[Jim V.]

Re: i always put side A towards the bearing

Thanks...makes sense. But, even under magnification this seal looks square...without any noticeable lips.... Even the removed seals which were probably OE look square. I can see how the originals would appear square though...given 100,000 miles of wear. Is there also such a thing as a square seal?
Thanks

[Phil P.]

where is the second lip ?

that seal like most all others will install with the crimped side towards the bearing with the A side towards the bearing which is the crimped side

[Rainer S.]

Re: i always put side A towards the bearing

There is no such a thing as a square seal. The only seal I have ever seen, that is sqare, is a "quad O-ring", but never a square seal. A square seal would leak, unless you pack it like on a pump.
The manufacturers National or CR,( Chicago Rawhide), are the most widely used seals for cars or machines. They all have similar designs, they ALL have lips, most have (1) lip, but many have double lips, of various designs. Most have a spring (called Garter Spring") on the main lip.
Google "oil seal" and you will see what I am talking about. I have books here at work, if you have a fax machine, I could fax you the page, which shows all the oil/grease seal designs.
You could install your seal either way, since it will keep dirt out. Grease will not try to get out. It would only be important when using seals with oil applications, like I stated earlier.

Rainer

[Joe L.]

Re: i always put side A towards the bearing

Rainer and Jim------

Well, this is somewhat of a mystery. Here's why: in the "old days", there were some wheel bearing seals manufactured and used both in PRODUCTION and SERVICE which did not have a "lip", per se. They were simply a "flat elastomer with a hole in it" sandwiched between 2 tanged steel plates which formed the shell of the seal. During the C2 and C3 era, this type of seal was used on Corvette rear spindle bearings, both inner and outer. I don't recall if it was used on the front wheel bearing inner seal, or not. However, I vaguely recall that it was.

Later, this type seal was replaced by lip type seals. Often, but not always, these were of bonded construction. In other words, the elastomer was permanently bonded to the seal shell. I believe that Chicago Rawhide "pioneered" this bonded seal type.

The mystery here is that the elastomer component of this seal appears like the early seals I described above. However, the box looks like a more-or-less current-production seal. I didn't know that this type seal was even made anymore.

[Rainer S.]

Re: i always put side A towards the bearing

Try this link:
www.construction-guide.com/oil-seals.htm

[Rainer S.]

Re: i always put side A towards the bearing

Joe, I entered my last post the same time you did, I did not read yours until after.
You are correct, I did see the type of seal you described, come to think of it.
We never used this seal on machines, it was probably used as a "dust Seal", rather than an oil/grease seal. You are correct, that CR pioneered the so called "Lip Seal" design. Lip seals is all I have seen used in the years past.
So what Jim may have is a very old design and indeed does not have a "Lip" as we know it.
So it can be installed either way.

Rainer

[Wayne W.]

Re: i always put side A towards the bearing

You guys are the seal experts, but the type seal shown is what has been supplied for many years on the rear and front axles of the C2 and C3 Corvettes. Except for a few Chicago Rawhide seals that I have run across, they are all like this, and I have never observed any lip, nor spring, just a piece of rubber sandwitched between the steel. Lately the rubber on some has become so thick that it will pinch and tear off the so called lip when installed. When installed the whole seal is deformed into the shape of a lip.

[Jim V.]

Re: i always put side A towards the bearing

Wow...you gota luv this place...what a wealth of knowledge! Thanks all! BTW A poster over on the CF suggested using a superior Chicago Rawhide SKF seal from Napa. I think I will check that seal out and report back. In the meantime, I will go with the FM A side (crimped) towards the grease and the B side facing inboard towards the spindle as recommended by several posters.

[Rainer S.]

Re: i always put side A towards the bearing

I guess, one never stops learning, even when its old technology.
I am most familiar with machine tool seal applications, which do not use this kind of seal, with such a simple design. There is an old engineering term we use: KIS - Keep it simple. If the seal works, why change it.

Rainer