Author Topic: CZ 85, gritty noise when thumb cocking it, finally figured it out  (Read 986 times)

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Offline M1A4ME

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My CZ 85 is the one I sort of rebuilt and had cerakoted two tone a few months back by Primary Machine.  I have no idea why the dogs "wanted" that pistol so bad when I wore it yesterday morning but I noticed it had a gritty sound when I cocked the hammer (after field stripping it this morning).  I could not see anything in the action that would make that gritty sound but I sure could hear it.

I tore it down, removed safeties, sear cage, grips, firing pin spring and cup/lanyard loop and went through it.  It had a few grains of burned powder (counted 3, one was pretty green color, one sort of tan/gold and one dirty looking) that I got out of the sear cage with a steel pick.  There was also some oil/crud her and there and I picked and scraped and wiped till I had it pretty clean.  I put it all back together, lubing as I went and cocked the hammer again.  DARN!!!  That gritting noise is still there!!

Man, I couldn't believe I'd missed any dirt/crud in it so I started to take it back apart again.  I got one grip panel off of it and put it up to my ear and cocked it slowly and I could hear the gritty noise much louder (soft rubber grips).

It was the hammer spring rubbing the sides of the spring cup/lanyard loop.  No noise from hammer down to half cock.  Gritty noise from just after half cock to full cock.  I'd never noticed it before.  The hammer spring rubs the spring cup.  Anyone ever polish that area before?  I'm sure it doesn't affect single action trigger pull, the spring is already compressed and the rubbing is done.  I kind of wonder if "slightly" affects double action trigger pull.
Better to have it and not need it, than to need it and not have it.  So, if you see me walking the dogs with my SIG 556R, its okay.

Offline FireMoose

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Re: CZ 85, gritty noise when thumb cocking it, finally figured it out
« Reply #1 on: October 25, 2016, 03:58:37 AM »
Interesting. I never noticed that creaking sound til I read your post and ran to check. I certainly didn't feel the rub in the pull of the trigger or hammer but there is a creaking noise just after half cock and only til about a third of the rest of the way.

Offline Oldwolf

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Re: CZ 85, gritty noise when thumb cocking it, finally figured it out
« Reply #2 on: October 25, 2016, 09:25:52 AM »
That's a new one to me too.

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Offline Stuart

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Re: CZ 85, gritty noise when thumb cocking it, finally figured it out
« Reply #3 on: October 25, 2016, 09:31:10 AM »
It happens from time to time. Other place is the firing pin block moving up in the slide at the of the trigger pull.
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Offline SlvrDragon50

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Re: CZ 85, gritty noise when thumb cocking it, finally figured it out
« Reply #4 on: October 25, 2016, 12:10:00 PM »
I don't have a gritty noise, but my hammer spring squeaks like crazy when I half cock it.

Offline rhart

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Re: CZ 85, gritty noise when thumb cocking it, finally figured it out
« Reply #5 on: October 25, 2016, 12:30:02 PM »
Lots of guys polish the strut. Could the strut be hanging up on the spring pushing it to one way or the other to rub against the spring cup/lanyard?
Musashi:
- In all forms of strategy, it is necessary to maintain the combat stance in everyday life and to make your everyday stance your combat stance. (situational awareness).
- You can only fight the way you practice.
- If you do not control the enemy, the enemy will control you.

Offline M1A4ME

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Re: CZ 85, gritty noise when thumb cocking it, finally figured it out
« Reply #6 on: October 25, 2016, 08:10:16 PM »
Lots of guys polish the strut. Could the strut be hanging up on the spring pushing it to one way or the other to rub against the spring cup/lanyard?

I didn't even think about that.  You could be right.  Now that I think about it, somewhere, not that long ago, I saw a hammer strut that wasn't nice and smooth.  It had little, I don't know what to call them, but they looked like little gouge marks on the corners of the strut.  It made me wonder what the inside of the spring looked like, then again, maybe the spring is hard enough to wear the strut, but not be worn as bad itself.  Now I need to take stuff apart again to see if it was one of my pistols or not.
Better to have it and not need it, than to need it and not have it.  So, if you see me walking the dogs with my SIG 556R, its okay.

Offline rhart

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Re: CZ 85, gritty noise when thumb cocking it, finally figured it out
« Reply #7 on: October 26, 2016, 07:40:36 AM »
In one of the online guides (KneelingAtlas?) I followed for my first project they recommend polishing the strut and so I have always done it. Every strut I've polished on a CZ (not a huge number - probably 6) has those little "dings" or crevasses or whatever the proper terminology is. Some aren't that noticeable until you start polishing them or really look close. I've never fully removed them, but I do round their edges off so they are less likely to hang up on a coil of the spring. I'm assuming that is why the online guide recommended doing it.
Musashi:
- In all forms of strategy, it is necessary to maintain the combat stance in everyday life and to make your everyday stance your combat stance. (situational awareness).
- You can only fight the way you practice.
- If you do not control the enemy, the enemy will control you.

 

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