This should be your switch:
(Available here:
http://macsautoparts.com/early-v8-fo...0R3CHL1073886/)
And this should be your knob:
(Available here:
https://secure435.hostgator.com/~dlv...=343&t=2072&tn=)
No horseshoe clip involved as you can see. If you don't have these two parts it won't work right.
If you want authentic trim you'll need this nut shown below:
(Available here:
https://secure435.hostgator.com/~dlv...tAddTpCart.y=4)
And here's how the knob with shaft go on and off:
My guess is that you are not installing the knob/shaft correctly. You have to push it in turned 1/4 turn to the left then straighten it up and it should be secure. That's how I put mine in and it worked just as described.
