If this McD cue has the stainless collar with the 3/8x16 QR pin,
the pin and collar are a single unit. The pin and collar are one pc.
You're not going to fix it by yourself. It's a horrible design.
I've written my analysis of this design on at least a couple of occasions.
Do a search if your interested.
To properly address this issue, the joint should be disassembled and rebuilt CORRECTLY.
You can still have the stainless collar and you can still have the QR pin.
The modification sets the NEW pin in the forearm rather than just sitting it on the surface of the collar.
The additional wght of the new/longer pin is off-set by the use of a thin-wall SS collar.
I've been doing these with some regularity as of late.
The result is a much stronger design.
HTHs, KJ