Drive shaft boot leaking

[nighthawk11]

Hi All,
I've developed a small leak at the drive shaft boot. It's not a static leak, but more like a drop or two after an extensive ride. After cleaning, it doesn't leak again until my next extended ride. From what I understand, it's a seal from the final drive to the shaft that's the culprit. I had new seals put into the final drive a few months ago, but neglected this seal. My questions are:
1) Is this a DYI project or should a shop handle this? I took my own final drive off and let them do those seals, so I'm not beyond taking my ride apart again.
2) Are these seals pressed in, or is it a simple insert and re-assemble?
3) I have links to the microfiche, but can someone please confirm the seals I need?

Thanks, Mark...

[redjay]

Hi, Are you sure its the oil from the final drive ? How about the oil seal behind the gear that is on the output of the transmission ?

[nighthawk11]

That's just it. I don't know 100% for sure. How can I tell?

Thanks...

[ringadingh]

Originally Posted by nighthawk11

That's just it. I don't know 100% for sure. How can I tell?

Thanks...

One will smell like gear oil and the transmission end will smell like motor oil. Im guessing it would be the final drive end. There is a seal there that is replaceable, I went to a local bearing supplier and picked one up for $8.00. If you do a search here I have listed the P/N and I think a couple photos. I think Gadgets page also has a article on how to do the job. Its not that difficult to do yourself, there is a lock ring that I tapped out with a punch unless you have the special tool to remove it. and there is a small setscrew that has to be loosened beforehand. The lockring is a backwards thread.

[nighthawk11]

It's definately gear oil. I know that smell very well. Thanks for the input. I'll check out your other posts tonight when I get home, and gadgets site again. Sounds like I'll be able to do this one myself. Might do some other lubing while I've got her apart too.
Thanks...

[macmac]

If the smell is of gear oil then it is the seal there. However the drive shaft should be checked out, and so the swingarm should be removed, so you can check the U Joint.

If this U Joint is bad it will snap as it turns and this will eat up any seals quickly.

There is a term called 'sling' and this is the action the gear oil uses to get to where it can ride the drive shaft up hill, and show as the leak you found.

The drive shaft doesn't have to have a bad U joint for the seal to wear and sling oil, but since the factory sent out many a bad joint in the first place NOT GREASED correctly, I suspect this might be what you find.

The U Joint must spin smoothly in order to roll out even power and stay in line. If one or more end caps have no grease the needle bearing wear, then stick and seize to finally burn out.

Any of this causes the shaft to snap, and it will snap most at the farthest distance from the joint, in this case at the gear box end.

[nighthawk11]

Interestingly enough, I went on a 75 mile cruise this weekend and it didn't leak a bit. It's a strange little booger......only wanting to leak when it wants. I'll continue to keep an eye on it. It may never happen again.

[nighthawk11]

Finally got around to taking off the final drive again. It was the front o-ring alright. Little sucker was split. Either way, I installed the spare I bought, then I lost my light. I'll button her up tomorrow and take her for a spin.

[redjay]

Hi, You replaced the oil seal in the final drive ? How bad a job was that ?
I have to do mine as soon as the bike comes out of storage. I found oil in the drive shaft tube (swing arm) when I did the swing arm service in the Fall. About an egg cup full.

[nighthawk11]

No, I replaced the final drive. I bought a used low milage unit. It looks brand new. The owner said the bike had 40 miles on it when it was crashed. I plan on ordering a seal and making the original my spare.

[macmac]

redjay, doing the seals are not to hard... Do all of them though...

I think you can cheat a bit of you want, other wise you need to do everything you would do to change just a rear tire.

The cheat is come by something close to another rear axel to use as a tool, and as you pull out the real one you slip in the toolish one, which will hold the rear wheel in place and it must. To assist you could even tie down the rear brake pedal so the caliper grabs the rear wheel hard.

Of course the saddle bags must be off, and probably the left side bag support must be off. (left side as seated)

With the real axel out, then you can undo the shock on the gear box side, and the 4 acorns to the drive shaft, and unless I forgot something the box should be in your hands...

Stab and pop the seals swap out the o ring, clean and grease the new seal wells.channels, lube the surfaces they seal, grease all splines and assemble it.

getting close to fitting you might need to release the rear brake and turn the wheel back and forth to line up splines.

There is a spacer you will need to not loose, but it is big, and one end is different than the other if I recall... That would be looked at with care so it ends up installed correctly the first time.

in order to do so You would have to start now holding that spacer on the gear box splin that engages the wheel, holding the spacer in place with the real axel and some grease.

Might take me an hour and half i suppose...

Is this a repeat leak on your bike, or the first one?

Any time a drive shaft seal goes early i suspect a bad U joint..