Well, Duh.

[bwringer]

During the North Carolina GS rally, I couldn't figure out where all my oil was going. I went through about a quart and a half in 2,000 miles, with no smoke coming out the pipes. (The crappy Cometic head gasket is seeping at the corners, but I knew that already, and it's not enough to cause the oil level to change.)

A clue arrived in the form of drops of oil on my right boot. Hmmm...

I checked under the ignition cover, and found some oil, and noted some residue on the engine. No drips, but a drop of oil was definitely coming out once in a while.

Sure enough, I pulled the ignition cover today, removed the ignition rotor and components, and found that I had installed the crankshaft seal backwards when I built this engine in 2007. Mystery solved.

Well, crap.

The wonder is that it DIDN'T leak at all for about 25,000 miles, and now it's only leaking a little bit.

Triple-check everything, kids. I knew better. Heck, there's a freaking arrow on the seal showing you which way it's supposed to be installed.

Two new seals are on the way. You know, just in case I screw up one of them.

Aaargh.

[Macmatic]

I thought I'd done the same thing on one of my forks when I changed a leaking seal recently and saw the spring visible from the top. I didn't remember that there was a spring on both sides and when I took the <2yr old seal out the scraper rings were pointing down so I still don't know why it failed but at least I know I didn't do something I'd have to blame on a PO!

/\/\ac

[Nessism]

It's not a "mistake" until you do something wrong twice.

[bwringer]

It's not a "mistake" until you do something wrong twice.

That's why I ordered two seals...

[marvinsc]

I see that even the Master is still learning said Grasshopper.

[mike_of_bbg]

Maybe not as duh as you think. Which way did you install it? All of the pictures in the manuals that I can find show the rubber side of that seal going out (the outside "lip" points in toward the engine). Yet in a thread a couple of weeks ago:

http://www.thegsresources.com/_forum/showthread.php?t=142773

RapidRay said the black rubber-coated side should go IN. I was rather confused by this and asked for (but never received) clarification. Is there some hidden benefit to installing it the other way (a la the half-moon seals) I wondered? I'd be mostly concerned that on these older engines the seal around the shaft might be positioned over corrosion on the crank end, causing premature failure.

[rapidray]

The pictures in the manual show the seal in the WRONG way! The black part of the seal goes IN towards the crank. If you doubt me, call George Bryce,III or Byron Hines, or Kim Barringer at Carolina Cycle. The ONLY time you install the right side crank seal with the black pointed out is on a DRAG motor that you're using a vacuum pump on. Ray.

[bwringer]

The pictures in the manual show the seal in the WRONG way! The black part of the seal goes IN towards the crank. If you doubt me, call George Bryce,III or Byron Hines, or Kim Barringer at Carolina Cycle. The ONLY time you install the right side crank seal with the black pointed out is on a DRAG motor that you're using a vacuum pump on. Ray.

Yup, what Ray said -- the seal is supposed to be installed with the "metal" side OUT and the rubber side "in". It looks backwards from every other seal, but if you look closely, there's an arrow that shows which way the shaft is supposed to rotate.

Some seals are not directional, but on the sealing surface for many, there are little "stripes" or ridges that sort of wipe the oil back into the engine (assuming the seal is installed correctly).

As I said, I'm sort of amazed that the thing didn't leak at all until recently.

Replacing it in situ will be sort of a challenge -- loosen the nearby case bolts and proceed, right? I think there are several people who have accomplished this, and I've replaced lots and lots of engine and transmission seals like this on cars.

[Nessism]

I'd leave the case bolts alone if possible; you can get a leak where oil runs sideways between the crankcase halfs and then down a case bolt and on to the ground. Most likely you can tap the seal in with some oil or Threebond on the outside to lube it.

[bwringer]

Update:

The new seal is in, and no one got hurt.

The crankshaft seal was really leaking pretty badly at the West Virginia rally, so Something Finally Had To Be Done. The right side of the bike was covered in oily filth, and my boot was coated with oil. Most untidy.

The project was easier than I thought, as it turned out.

I used a small cold chisel to cut a slot in the body of the old seal, then pried it out with a pry bar (my Very Large Screwdriver just flexed uselessly).

There was a stubborn layer of rubber from the seal stuck to the cases. With a layer of plain brown grease on the bearing to catch abrasive particles, I cleaned things up with fine sandpaper and slightly beveled the edges.

After greasing the bore of the seal and coating the outside with ThreeBond case sealer, I slowly pressed it in with a Very Large Socket, using a long bolt threaded into the crankshaft with a washer and nut on the bolt. Easier and far more controlled than using a hammer and hunka pipe to bash it in. No case loosening was needed.

100 miles so far and no more dripping!