Skool Me On Synchro Function?

Thank you guys! That's what I needed to know. I hate doing monkey -see, monkey - do steps without knowing what's going on.

Now, I'm armed and dangerous!:elmer:
I'm not sure but I bought my rebuild kit from Brewers and I want to say they were fifty bucks for the set I hope! LOL and not 50 bucks each but while I had it apart...