That part it is attached to is listed as a 'Drive Lever A-8307'. The smaller attachments are called 'Drive Arms'

Not really sure.

I have had a lot of trouble with these and altering the stop brackets makes massive difference and has usually fixed many.

Factory is with spring so try and get it functioning 100% with spring

Sounds like the red tab may be bent and interferes where it should clear.

The bigger issue that often happens is the pivot of the arm with the part number arrow A-2439 will gum up and not follow the toothed cam keeping the unit from stepping up properly.

Hard to say without having it in front of me.
But I will say that Gottlieb didn't install extra parts that serve no purpose.
I'd check MikeO's suggestion above and ensure that all pivot points allow the various arms to pivot easily.
--
Chris Hibler - CARGPB #31
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What have you done to this unit so far?

I have rebuilt many of these and never encountered the issue you describe when properly assembled.

If the toothed wheel moves out too far, the mechs can hang up on the wheel. Also, as mentioned before, the pivot points are critical.

I believe that "green bit" actuates the knocker switch, so if you futz with it, I would expect a knocker malfunction. Perhaps double or triple knocks. Or, the lever just sitting on the switch and burning up your coil.

I agree with ChrisH - it's hard to say without seeing it. Here's a closeup of one that works mechanically as it should.

Gottlieb_Credit_Unit_(resized).jpg

Things to check include:

- Are the springs all connected to the correct holes? The short spring connected to the part you're having trouble with should be connected to the lower, outer hole on the end of the lever arm.
- Is the part moving freely? The green tab you highlighted should remain parallel with the lever arm behind it as it moves.
- Are the various parts in the right place relative to each other? I don't think the green and red tabs should touch normally.
- Are the stops for the lever arm adjusted properly? The arm should swing just enough to engage a tooth on wheel and advance it, not much more.

Looking at it closely, I too have to wonder what that part is for.

/Mark