why does the over center spring have to be removed

I am having a diaphragm clutch installed as we speak, I went to the shop to see what was happening, the car is a 73 duster 340 that had a borg and beck 3 finger unit in that was a bear to use in traffic. any how they got the clutch in but the guy said he was having trouble getting into second, so he showed me the adjusting rod and says it is worn out. I could see some wear, but does not look to far off from a new one, he says it should not be oval shaped, but a new one is oval not round , he said you could not tell it was worn until the retaining clip was removed to see it. also I am not sure if he removed the over center under dash spring, that should come out with a diaphragm unit--- correct? could this be the problem and not the adjusting rod??? thanks