I am doing this on a 97 Arctic Cat ZRT 600 but it may apply to other brands also (I am sure it applies to other arctic cats)
The speedo failing is not always a sign of drive shaft bearing failure but alot of people say it is.
What could have happend -
1. bearing siezed, wore out tunnel, moved back and destroyed the key
2. speedo drive gear broke inside itself. Here is one
http://cgi.ebay.com/ebaymotors/95-Arctic-Cat-ZRT-800-speedo-Cable-drive-gear_W0QQcmdZViewItemQQcategoryZ100458QQihZ006QQitemZ160200618798QQrdZ1QQsspagenameZWDVW
Thats for a ZRT but yours might be the same (have to double check part numbers). I recently had a member on here PM me and his speedo broke. Told him what I am telling you, turned out it was that part I just linked up. When that locks up, key breaks, no speedo
3. Cable problem- Cable locks up or too hard to turn, key breaks
4. Speedo problem - mechanism in the speedo goes, key breaks
5. Center piece in axle stripped out
6. Bearing froze up, wore out bearings, inner race moved and broke key.
To diagnose- Undo cable from speedo drive gear, put it in a power drill and pull trigger in right direction. If speedo works, no problem in cable or speedo itself.
Take off drive gear
If there is a key sticking out of it, hang onto it and rotate your secondary (with track up in the air). If key turns, no problem there.
The part that was inside the above picture is pressed in there and the key slides into it. See below
speedo adapter
IF you had made it this far that means all that stuff checks out ok and you have a problem with your speedo gear.
You can stick the key in the inside hole and turn it, if it turns hard or doesn't turn at all, broke. If it turns ok, look at the outside part where the speedo cable connects. If that isn't turning when you turn the inside one, broke.
