oil drip from rubber boot on drive shaft

[arlene]

just changed all the oil in bike and transmission. Now I am getting some drips from the rubber boot that covers the driveshaft and output shaft on R100/7. Any Ideas what this could be.

[johnnyb]

There's a thread on page 4 of airheads about this. You may want to check it out.
I'm guessing you changed the driveshaft oil too.
Johnny

[arlene]

Ya.....I did. I have not had any leaks up to this point so not sure why this would suddenly happen. Thanks for the tip. I will check the page. So I read the post and it sounds like that might be it. I was pretty careful to add the right amount. Just hopeing it was not something super serious as I am heading for a bike trip in a week.

[Na Cl K9]

Keeping a good rubber boot in place at all times is an important part of maintaining the reliability of the airhead driveshaft. A fresh rubber boot and secure clamps are essential.

Look at the top of the rubber bellows and find the mould line. Carefully push the bellows apart at that point so that you can look down into the "valley" between the "peaks". If you see web-like cracks appear in the rubber there as the bellows are pushed further apart stop! Cracks are present underneath as well and the boot needs to be replaced. The cracks I refer to are similar to those you might notice in an old tire sidewall and are the result of age. Often, this is called "Dry Rot" or "Weather Checking". As the dry cracked boot flexes, oil seeps through the cracks and causes a drip. Sometimes, if the boot is really old and badly weathered, pushing the bellows apart will cause it to rip open forcing you to deal with the problem immediately.

I have imagined a temporary complete boot replacement on the road using duct tape. It would make a great segment for the Red Green show...

Occasionally the swingarm-side boot clamp will loosen and let a little oil get by. You will find oil underneath the swingarm around the boot. There will seldom be leaks around the transmission flange because even with the clamp loose, the boot fits snugly on this flange. Another place leaks develop is where the boot fits over the underside of the swingarm bell. There is movement and stretch at the spot where the clamp and the edge of the bell come together and with the rubber boot sandwiched in between, a tear can develop as the boot ages. At most, a parts list to perform the necessary repairs would include a fresh new rubber boot, two new boot clamps and four drive shaft flange bolts.

First, find out where the drip is coming from. You might be able to check the leak by simply tightening the boot clamp. If it looks like cracks are just beginning to develop and the boot feels like rubber should, flexible and soft, then you can probably run it for a while longer. Try and replace the boot at every “service opportunity” so it becomes a part expensed to a more complex job like spline lube rather than paying labor to replace only the boot.

[arlene]

Hey Thanks for the reply. I just wanted to make sure that the oil dripping from the boot was most likely nothing serious. I have had this bike for about 5 years, and it has been pretty oil tight, but just started leaking around the boot. I am assuming the oil that is in the boot is just the "flung" oil from the bevel case. I also may have put a bit too much oil in. I fussed with the clamps and boot and am getting only a drop or 2 leaking out for the day. I will check on a new boot and clamps at next service. Thanks again