Same here! Teeny bit wobbly. Mine also leans a bit at rest a few millimeters to the right. I've studied the mechanism & there isn't a lot to the parts that hold the kicker in place. Basically a shaft that sits in a guide. My shaft is perfectly square; but I noticed that the guide that the shaft rests in is a bit rounded in each "corner" of the square & has a notch in the top for the kicker at rest. The shaft can move around in the guide due to these rounded corners from what I can tell. However, the replacement part I've found for these have the "rounded corners" built into the square guide bracket already. In the end I wonder how tight the shaft is really supposed to be within the guide anyway. If the guide were any tighter, the shaft might not move properly inside it to kick the ball. I wonder if there is any tension on the spring on the shaft itself that holds the guide upright? I've seen pictures of Shadow guides at rest & there's def a mix of leaning vs upright. Very interesting stuff!

So I said my shaft was square (ha!); but if I run my fingernail down the side I can feel a teeny ridge. We're talking fractions of a mil here. That may be contributing as you said. Is this the guide part we're talking about?:

http://www.marcospecialties.com/pinball-parts/01-12449.1

I'm wondering if over time both the guide & the shaft lose a fractional amount of material that causes the looseness? I checked the spring behind & it just floats. It doesn't seem to provide any rotational tension (which might resolve the issue actually.) I haven't tried clamping the guide together or disassembling for that matter. Seems like we'd simply want to replace the guide + the shaft to reset the pieces to their original sizes. But like you said, where does one get that square shaft & what's the part number?

So I just finished screwing around with mine a bit. Came back here to see you guys had basically solved the problem! Freddy is right on; it's all about that guide hole. My big hangup wasn't the play in the kicker during a game; there's a bit, but not too much. My OCD issue was the kicker leaning to the right at rest. I started by actually twisting the entire guide a bit to the left to compensate; no dice. This actually impeded the kicker from "kicking" properly, too much friction in the guide now & I could see that it was going to hangup + wear badly. Put it back. Then I slightly bent the right "tooth" at the top of the guide so the kicker arm actually rested on it when it was in the resting position. Fixed! Straight up & down + the kicker still kicks smoothly. So it really is all about the guide/guide hole & a little adjustment changes a lot on the kicker itself. So gwynners, thanks for bringing this issue forward again, didn't realize how much it was irritating me until you said something.

So, I've def made that shot just like your diagram shows (just did it to make sure..in fact got 2 shadow loops in a row ). However, most of the time it will ricochet between 1 and 2 a couple of times and head on down. I'm sure there's some skill involved (of which I have none.) Let us know how the adjustment goes!