Swing arm leaking

[Einar]

I once again call upon your expertise as I am getting closer to the end of my first R65 restoration.

Only 1 (!) leak left, and I have postponed this one as long as I could...

I have an oil seep at the swing arm. I believe it is coming from the accordion rubber at the transmission end (see picture) that is sealing over a rather uneven circular surface (the gimbal joint?..). I noticed the leak because i have black oil damp around the area as well as oil drops hanging on the clutch lever below the joint.

This would be transmission oil, right?
I have regularly checked the tranny oil level, and it is not decreasing much, so I guess it might not leak while driving, but rather after being parked and before it has cooled down. Does that make sense?

As the surface is uneven I assume some seeping could be expected but I'd like to close it if possible. It is however little space to work with in this area and I don't want to make things worse as I have no experience with this part of the bike.
I have tried to loosen/move/re-tighten the screw but I didn't manage to move it much and the pad eyes on the metal ring started to bend. So I stopped.

Basically I'm wondering if this is a common problem and if there is a way to stop the leak without taking apart the swing arm?

Your input is highly appreciated.

[Bob_Roller]

I don't know if this will make any difference or not, but the area were you have the arrow, the rubber boot isn't positioned properly under the clamp .

There is a small lip at the back side of the boot, it should not be under the clamp .

Just be fore warned, working on this boot, is an adventure in frustration !!!!!
[ch128547][timestamp=1470242091]

[georgesgiralt]

Hello Einar,
On the underside of the swing arm, there is a metal  tang  to hold the rubber boot. If the boot is not properly placed under this tang, there are leaks;..
Also, the metal ring has to be placed perfectly to seal the leaks.
It is a job to undertake after a loong Yoga tuition or your preferred method of steam reduction ...
Prepare a vast collection of bad words, you'll need them too.

[montmil]

The "molded" ridge visible at the top of the boot should be at the bottom.

Your red arrow indicates the boot is misaligned with the driveshaft's housing and the correct install position; most likely the source of the drips. Drip could be due to PO's incorrect install. Could also be a crack or tear in the rubber boot along the bottom. An inspection mirror would be helpful here.

Replacing the boot should be on your "to do" list. You will need, according to veteran gurus, new bolts to reattach the u-joint to the trans. Some folks reuse the bolts and they are not dead yet. NOTE: You may find washers used with the four attach bolts. New bolts are shorter and the washers should not be used as there will not be as much grip length as required. Torquing the bolts to spec, well, when you get there... Holler.

It's a frustrating chore. I hear that using one of your air filter box spring clips can reduce the pain. I learned that after I replaced a split boot.

You have our sympathies. [ch128527]

[donbmw]

The drive shaft has its own oil from the transmission. By the look of the picture that boot has a tear in it.


Don

[mrclubike]

The last time i ordered a new boot I mistakenly ordered the Boot for a Air Head Paralever  
Will when I discovered this it was completely together and all i had left to do was install the boot and clamps
The  trans side went on with a little tension as normal but the tube end slide right on with no trouble.
I had nothing to loose so I went ahead and put the clamp on and ran it that way
After about   2000 miles I have no leaks and it was a lot easier to install
By the way the boot I removed and the throw out bearing boot lasted less than 2 years

[montmil]

The drive shaft has its own oil from the transmission. By the look of the picture that boot has a tear in it.


Don

Good eye, Don. I flat missed that.

And Einar, keep the clamp screws on top of the boot to insure a better seal down low where gravity can be unkind.

[Tony Smith]

That boot is history.

If your transmission oil level is dropping so is at least one gearbox oil seal, and given where the leak is, my money is on the rear trans seal.

I have had driveshaft flange bolts loosen and let go (it is quite a mind focusing event when it happens let me tell you) and as a result I am firmly in the "buy new bolts" camp, they are no expensive against the cost of the  seals. The boot is quite cheap too.

Best thing ever for fitting a new boot are some angled artery forceps - these are surprisingly cheap brand, can be had 2nd hand on fleabay and if you have a friend in the medical trade you might be able to hit them up for three of them. I was amazed at how easy they made the "fitting new boot" job.

As your gearbox is coming out, I would buy all new seals and a new clutch plate in addition to the boot and bolts. You may also need a new pressure plate/driven plate combo, but you won't know till you get there.

Oh, a few last things - you can get the drive shaft flange off by scrounging a suitable round piece of plate, at least .25" in thickness and drilling 6 holes in it - 4 to bolt it to the output flange and two tapped to suit your favourite bearing puller. Or you can buy a special tool for around $75US.

The output shaft is on a taper - this is a not too bad idea but it requires very careful putting back together - you can check if anything nasty has happened using Prussian blue, but if it was together properly when you took it apart, chances are this would tell you nothing useful.

Do coat the tapers in grease when you seperate them so that they do not ruse and do polish them furiously after a careful degrease before putting them back together (clean and DRY is the secret). This is one of the more "careful" jobs you do on our Boxer toys.

[donbmw]

The drive shaft has its own oil from the transmission. By the look of the picture that boot has a tear in it.


Don

Good eye, Don. I flat missed that.

And Einar, keep the clamp screws on top of the boot to insure a better seal down low where gravity can be unkind.

That jumped out to me when I looked at the picture.

Don

[Einar]

Hello everyone and thanks for the invaluable input.
Apologies for the late reply, I am currently traveling with limited coverage.

I was able to stop the leak (it appears) just before going away. I will probably need to address the more fundamental problems later (tony's comments) but after repositioning the boot and adjusting + tighten clamp she shows no sign of leakage after a 10-mile ride. I'll test further when I return.

I managed to remain relatively calm but steam reduction measures were needed towards the end.