Glad I pulled my swingarm.

[Pizza Guzzi]

A quick search reveals this topic has been covered before here with some valuable insights provided so I'm just adding my findings to what's been said already.
Bike is V7 111 Special for reference.
Pulled the swingarm as I knew there were possible issues with water getting inside the casing and there was a total of maybe 50ml in there mostly pooled down the bevelbox end and heavy condensation over everything else - drive shaft, uni, inside of swingarm casting. Some surface rust on the pinion retaining nut and a minor bit on the uni joint.
IMHO and as smithswede and others have mentioned the problem relates to the way the rubber bellows is located into the swingarm.  A sort of internal circlip inside the boot pushes the boot into a corresponding groove in the swingarm casting. The clip is not a full circle however, there's a gap of about 25mm between the two ends when installed so not only is 25mm of the boot is not pushed into its groove the 25 mm portion of the boot not covered by the spring is actively pulled away from the groove leaving a gap that you could easily slide a match stick through.
It doesn't help that this is in about the 11 o'clock position either. As smithswede did I've sealed it all with silicone and put a small vent hole on the lowest portion of the boot. Seems to be zero problem with the attachment of the boot to the transmission case despite the fact it's got a cheap and nasty cable tie securing it. I couldn't see any evidence of water entering on the flange where the bevel box mounts.
For the record the driveshaft splines were dry on the uni joint end and lightly greased on the bevel box end.

Glenn

[AaronH]

Thanks for posting this.  I am going to check mine and grease/seal it.  . 

[kingoffleece]

I'll pull my 2015 V7 this spring.

[guzzisteve]

I think everyone should be sending the company letters to inform them that they are making their product wrong. Better yet go to the factory and instruct them on how to build their motorcycles. This is the only way it will get fixed to your liking. You should have had it done under warranty at the dealer.

[SmithSwede]

I sealed mine up about 60,000 miles ago and it’s been as dry as a bone inside ever since.   And I’ve ridden through many a frog drowner.    Before I did that it would collect water.

FYI, if you have your silicone goop out, I highly recommend sealing up two other things:

—The speedo/odo sensor on the rear wheel.  Mine got wet and the gauges went crazy for a while.  Had to dry it out with a hair dryer. 

—the spark plug wires where they enter the spark plug caps.  Failing to do that cost me hundreds of $ for a tow.

[Pizza Guzzi]

Forgot to mention that despite water pooling in the swingarm there was no contamination of the bevel box oil so it seems the pinion bearing seal is doing its job.

Glenn.

[Andy1]

So did you use the silicon to hold the rubber bellows in their groove?  Or use the silicon to fill the gap?

Venting will be essential if fully sealed.  No chance of a hole in the rubber leading to a tear?  Another way might be to drill a small hole in the bottom of the swingarm casting, at the rear end where it is lowest?

To stop water building up on the top of the bevel box I have drilled holes though the bottom of the ‘fins’ so that water can drain out, but this was really a very minor issue.

Thanks for all the advice

AndyB

[Pizza Guzzi]

Andy I left the retaining ring in place and siliconed the gap, I also ran a bead around the circumference of the boot. Swingarm, boot and silicone are all black so it's not really noticeable where I sealed it.
I used a piece of hot wire to put a small hole in the bottom of the boot to act as a vent. Time will tell if it leads to a split but I suspect it's ok.

Glenn.

[Huzo]

If you're gunna' pull something, it might as well be your swingarm...

[Toecutter]

When I pulled mine off for the first time... the factory had installed the circlip in such a way that about 1.5 cm of the boot wasn't even clipped in. Provided a wide open hole allowing water and sand in, and some sand had worked it's way into the groove, and worn through another area on the boot.. That thing is kind of a bugger to install properly, too.

I bought a few of them to have on hand.

[jbell]

If you're gunna' pull something, it might as well be your swingarm...

If it makes you glad, I guess you're doing it right.

[SmithSwede]

I generously slathered silicon goop everywhere on the boot I thought it would do some good.

And yes, once sealed you need to put a tiny hole in the rubber so it will vent.  Mine has not split. 

I used to worry that the little vent hole would let some water in during a heavy downpour.    But it doesn’t seem to.   Or it lets in so little water that it easily evaporates out the same hole. 

[jacksonracingcomau]

why do you want to vent the boot ?
 no pressure in there afaik
for the record I sealed mine with waterproof grease  no vent, splash of gear oil in there too will look again next tyre but the coupling is my real concern —v7/3 v9 rear end looks a lot better to me