My dad has a 1993 Panther 440. On the 19th of Feb, we were coming back from a derby when the bracket that holds the jackshaft by the clutch ripped off and the clutch went forward. Of course he couldn't drive because the belt was too loose after this, so we towed him back. What could have caused this, and how much will it cost to fix?

The bracket holding the bearing could have been broke and it finally gave way.
When was the last time the jackshaft bearing was replaced? If it has been awhile, the bearing could have froze up and ripped the bracket off due to the rotational forces of the jackshaft.

I don't think the bearing has ever been replaced. The sled has about 8600 miles on it though, so you've got to expect something to go at this point. I don't think there was alot of maintenance done to it.

Well now would be a good time to do some maintenance on it. The bearing support bracket is not that difficult to change. Threre are three bolts that hold it on. The only part of the job that may be difficult is that the rear skid has to be removed, along with the track. But since these items are coming out, replacing all the bearings in the rear skid, chaincase, and track drivers should be no problem.