jkingston
286
A Theory On Why the Cap Is Used
This is largely supposition on my part, but here goes. In general quite a bit of lubrication is required around the column wheel. The wheel itself needs lubrication in order to turn freely. As well so do the fingers that cause it to turn and the fingers that are manipulated by it when it turns. There is a risk that these lubrication points will show the oil that is applied to them. As this is somewhat unsightly, a finely finished cap placed on top will do the trick to place all of this out of sight.
Jeff