Leak at u joint boot?

[Bob_Roller]

The job isn't that difficult, but the first time it will try your patience, I have been warming the rubber boot up with a hair dryer, once it gets pliable, it stays in place  .

The biggest challenge, is that you can secure one side of it, but the boot keeps creeping back when you start installing it on the other end, that's when heating up the boot  helps .

 I start by installing the clamp on the aft side, before going to the front or forward end .

Also when you have the boot in hand, look for the word 'OBEN' molded into the rubber, this goes up .

 My German is rusty, but I think it means top or up .    

[weasel01]

OK... so I'm ordering my parts and the manual says replace the gasket at the swing arm bearings each time the are removerd but the parts fiche only give a part number for "Up to 1981" I have an '83 and when I called Chicago BMW they didnt even have a current listing you guys have any idea what I should do?

[Bob_Roller]

The only thing on the bearings is a large flat washer .

The bearings usually don't get in too bad of shape, and they don't rotate, they just move in a small arc .

Pump some grease in there every time you wash the bike, and you shouldn't have any issues with them .

[weasel01]

So I ordered the new boot 2 new clamps 4 new bolts and I also got the seal at the final drive as I'm getting some leakage from the drive shaft into the final drive.
I'm hoping that will be straight forward but I havent read up on it yet.
Thanks Bob for the heads up on the swingarm not using the seal...

[steve hawkins]

I would say fiddly and a little bit frustrating.

Sometimes it can take 30 secs, and other times 30 mins and some swearing.

That is all.

[weasel01]

well....the boot had to be ordered from bmw on my order from chicago bmw so I went out to the garage and thought I might  clean it up and check the clamps and each clamp had about a turn and a half left so I cranked em' down but it looks like the back clamp is already embedded in the rubber...maybe it will slow while I wait for the backorder....

[Justin B.]

Moto-Bins usually has them in stock for less and quicker - even with postage from across the pond...

[steve hawkins]

You could aways clean it up and use a punture repair kit, if you can identify where the leak is coming from and its not a clamp issue.

I have seen it done successfully and the fix lasted years, although he eventually did change it.

Just a thought to keep you going.

Steve H

[Justin B.]

I have put a smear of silicone over slight cracks that were just starting to seep.  I did this on the '95 R100RT and that prolonged by boot replacement about two years - until the tranny went south!  

[weasel01]

The weather has decided to clear up today so tonight I'm gonna take a ride and see if there is any improvement in the leaky boot....

Got all my special tools in the mail yesterday but the boot's back ordered for a week so theres no sense in dropping the swingarm to do the spline lube and then turn around and drop it again when the boot gets here....or is it straight forwrd enough to do twice?

drat....weekends are tinkertime dangit.

[weasel01]

The tranny didnt go south cause of the leaky boot did it?

[Justin B.]

No, just your "typical" BMW tranny bearing failure.  I changed it when it was just starting to get rough so nothing else got torn up.  The rear bearing was the worst.

[weasel01]

Well...I went out for a nice long ride last night and when I got home I parked the bike looked at the boot and not a single drop of oil....went inside pulled a fresh beer off my kegerator walked back outside to marvel at the boot fix and just as I looked down there a drip formed in the same place and started to dribble down the back wall of the tranny......DRAT.
Guess I'll just have to wait for the boot to show up before I drop the rear end....bummer

[weasel01]

Justin, is typical bmw bearing failure due to high miles?

[Bob_Roller]

Well, with a 26 year old vehicle, rubber parts just need to be replaced, there's no real way of getting around the age issues with our bikes .

Once you get it all sorted out, you don't have to get concerned about these things for quite some time .

Just had a thought, have you checked the bolt that secures the ground cable from the battery to the transmission ?

It is a hollow bolt, and serves as the breather vent for the transmission .

If it's clogged, the transmission my be 'pressurizing' when it gets up to operating temperature .