Kiwi- What has convinced you that the gearbox was in bad enough shape to cause a lockup? That is a fairly rare scenario. It can happen where the clutches not being used get hot and seize, that can be determined by blue steel discs, burn clutch facing and burnt oil. Did gear case ever get super hot?
Just trying to make sure you are on the right path...
Hi
I pulled the gearbox off and the engine turned fine,
Just as i was losing hope I heard back from the Capitol guys with a full service manual and a conformation that service parts are still available. Today I pulled the gearbox apart and removed the clutch assembly, when turning the center spline i could feel a rough spot, after turning clock and anti clock wise by hand it locked up proving that I had found the problem.
I have passed the clutch assembly to an old timer mechanic to take apart and check for the failed part, fingers crossed it may only need a new bearing.
The last 24hrs i went from disaster to hopeful so I will be keeping my old capitol after all, I believe that they are pretty bullet proof if maintained well, mine is a very early model late 60's so knowing spares are available is awesome and will save me thousands in installing a brand new gearbox.
Lesson learnt is don't give up to soon. (unless you have money to burn)
From the comments and threads it is a highly unusual problem, For the future I have learned to write down as much info as i can at the time of something going wrong. so diagnosing a problem is easier, when the Sh!t hits the fan you don't remember the exact details of everything you check like can you turn the engine in both directions, is the shaft locked up etc etc, especially with intermittent issues.
