850man wrote:
The throw out nuts are a carry over from the spring type clutch diaphragm, and the early slave cylinder, that did not have a circlip fitted. Pumping the clutch quickly would not give the master cylinder enough chance to return the fluid and it would pump the slave cylinder piston all the way out. The overthrow nuts, adjusted to spec would stop this.
Once the circlip type slave cylinder was introduced, it stopped the possibility of overthrow and made the nuts redundant.
The only way they can overthrow is if the rod has been extended and the freeplay adjustment done up too tight, or the throw out thrust bearing spaced out from the carrier.
The spring is fitted to help return the arm, and it holds the thrust bearing away from the thrust plate.
Ta!