I can't find, and shimano no longer supports their high dollar FH-7700 DA hub, part number 3AO-0900 left hand dust cap. Any body know of a shop that might have one? I hate to glue the thing in place, because it makes servicing the hub a little more difficult. It has loosened to the point that the seal on the hub cone rotates the cap leaving black plastic dust in the hub and fouls the grease.
I tried Paul Morningstar, but he doesn't seem interested in making one.

David

donor hub

Spray a bit of WD40 or whatever on the hub, letting it dry to a residue. Then use silicone; it should make a nice grippy seal that will stay attached to the plastic bit if you're lucky.

There're some on ebay right now....

Buy another one = last resort for folks born with a screwdriver in their hand.

What's that suppose to mean?

Gave up. Epoxied the thing in place and ordered an old 600 series from Loose screws that I will put an 8 speed freehub on. It will out last me and my kids if they ever start to ride. The new and imrpoved stuff isn't meant for someone who rides 12 to 14k miles a year. It just doesn't hold up as well.
If I hadn't found this one I would have bought a Formula hub with radial bearings.

Since properly set up hubs last practically forever, there are plenty of nice old ones around... the trick is finding the gear, I guess.

Here's a tip: if there's a local charity who donate bikes to the third world, they probably have a bunch of road bikes they can't use...

The problem is that the part is in the hub and wears out in time. So an used one may not solve the problem. I am annoyed that shimano doesn't support their top-of-line components for as long as well cared for parts last.

Really not seeing the issue here, the hub you have is 4 generations old, and it's 10+ years since they were introduced, which other large bike manufactures still provide individual spares after this time? Shimano are one of the best to support their older components, but they won't support forever, 2 generations is normally the limit; and 7700 is way over this. it's not as if they don't produce hubs which are not 9 speed compatible still, as their whole range less 9700 will work with 9 speed.