Can someone explain to me how this linkage works?

[Alwaysonauto]

How the red circled joint works?
Is this a spring holding the arm on the shaft which, I assume, is splined?
Thanks for helping this old new guy out.

 

[332_RC]

Servo saver! It has a lock in there, that if in an impact, it will overcome it, not break, & the spring returns it. Keep on trucking

 

[Alwaysonauto]

OK, thanks!
Like I said, I'm new to this new stuff, my old Frog didn't have anything like that if I remember correctly, which could be questionable at my age now.

 

[Suburban_Hooligan]

 

[Alwaysonauto]

Thanks, S_H, I had to look really closely with a magnifying glass to see the parting line on mine. Your picture helped a lot.

 

[CertifiedMike]

Your Frog had a servo saver more like this I bet.
Same idea, different design.

 

[Alwaysonauto]

Looks vaguely familiar but it was over 40 yrs ago.

 

[CertifiedMike]

Looks vaguely familiar but it was over 40 yrs ago.

I say the same thing when I see my feet.