After my latest range session I decided to flush out the frame in my 5906TSW with some gun scrubber which blasted out a fair amount of gunk and oil. Afterwards the firing pin safety lever seemed a little loose and I can hear it rattling in the gun now when I shake it even when it's fully reassembled though it seems to function normally. Is this normal to happen and the lever was just being held tighter by accumulated crud before? Is there a way to safely check if the safety lever is functioning properly?

I wouldn't think that the lever would have enough mass, and be sloppy enough it it's dovetail for it to make noise. Hold it by the lever/s and shake again. See if the noise is still present. My guess would be slide to frame fit.

It's definitely the safety lever, the slide to frame fit has always been really tight and never made noises before when shaking the gun. The safety lever seems to be flopping up and down past where it would normally rest on the spring and making noises when it does and I'm not sure if it's supposed to do that.

When properly installed, the firing pin safety lever is captured between the "ejector spring" (one of those two little springs in the frame that sit under the three levers) and the "firing pin safety lever plunger spring" in the slide which pushes down the plunger that actually blocks the firing pin.

So it seems to me that the firing pin safety lever isn't likely to do much rattling under those conditions.

You mentioned "the firing pin safety lever seemed a little loose".

With the slide off, the firing pin safety lever (#3 on the right") should be held up by the little spring it shares with the sear release lever next to it.

If it is flopping around, maybe the little spring is missing?

Anyway, kinda hard to tell without pictures, at least.

John

My 5906 doesn't rattle when shaken. I'll trade you straight across.

Forgive me, as I misunderstood in my first response. I thought you were referring to the THUMB-safety lever, aka decocker.

My vote is missing or broken spring - maybe there was enough crud to compensate.