CM400 Speedometer repair(?)

UPDATE 8/6/2013 : I've put about 1,500 miles on the bike since this repair. Everything is working well. It does tend to get a little moisture in it when it sits in the rain, but a couple days in the dry and everything is good to go. My tach has started doing the same needle wobble that this speedo was doing a while back. I'll probably do this same repair to the tach over the winter.

 Tools required: Wrench to get the speedo off the bike. Pull on the wires and the bulbs will come out. Needlenose pliers help you get some leverage.

Once disconnected, all you need is a pair of pliers, a screwdriver, and something to do some prying with. I used hardened steel picks. A dremel tool will also be helpful to cut the crimp band that holds everything together. NOTE: This band is not designed to come off. If you break it, you will need a new one when you reassemble. Alternatively, if you don't care about how it looks, you can use some adhesive and re-crimp to the best of your ability.

This is the crimped band. I used a hacksaw (no idea where my dremel went) for the large section that I could get to, then pried and pulled with the pick and pliers to break the hold. After that, the whole thing comes apart pretty easily.

Adhesive was used to hold the rubber seals on this sucker. Mine had a small compliment of rust in addition to that. I was able to pry it apart fairly carefully without destroying the rubber. When reassembling, put small dots of adhesive back in these areas.

Here are all the pieces of the major assembly once they came apart. Not bad at all.

Once you've got it separated, you can get to and lube a bunch of the pieces, but NOT the most important one.

This little area in red is what is responsible for the whirring/whining noise that comes from the speedometer. It was once well lubricated internally with some form of grease. Over the last 30+ years, that lubrication has dried up and disappeared.

If you can get to the inside of this thing, you can lubricate it.

TEST it once you think you've got it. You can put the speedo back on the bike with the housing/glass missing. It will work just fine. Only once you've tested it should you spend the time to put the whole assembly back together.

Not having the ability to reassemble the metal crimp that I murdered, I opted for a very tight wrap of electrical tape to hold the housing on. Seems solid for now. (1500 miles later, still going strong).