Diagnosis request for Glock 17 malfunction

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I have a G17 Gen 3 that has a Zev modified frame, Zev trigger and whatever else they offer as mods. For the slide, it has an Agency Arms barrel and, possibly, other mods but it's a stock Glock slide otherwise.

The malfunction is that the trigger fails to reset about 1/3 of the time. If I shoot, the slide cycles enough to load the next round but the trigger does not reset. If I manually cycle the slide, the trigger always resets.

Any thoughts on what the issue would be?
 
OP- during live fire, is the slide going completely into battery?

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in terms of the trigger spring, on a glock a heavier trigger spring will paradoxically lighten the trigger pull. resistance in the trigger is created by the striker block spring, striker spring itself and to some extent the disconnector.

i have no experience with these gucci glocks (i run mine stock), but my understanding is they employ lighter striker- and striker block- springs. my first move would be to remove the firing pin and clean out the striker channel, ensure the striker assembly is moving freely and able to push the trigger forward against resistance. if the striker channel is compromised either by gunk or a wonky firing pin channel liner then the striker spring will not be able to push that trigger bar back forward.
 
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make sure that the trigger spring is installed in the correct direction. AS you look down at the trigger mechanism housing the spring should hook OVER the housing and UNDER the trigger bar/cruciform. I put one in backwards once and had the reset problems you are describing.
 
make sure that the trigger spring is installed in the correct direction. AS you look down at the trigger mechanism housing the spring should hook OVER the housing and UNDER the trigger bar/cruciform. I put one in backwards once and had the reset problems you are describing.

^this for sure. if it the spring is in backwards it won't apply the correct downward pressure on the sear/trigger-bar
 
make sure that the trigger spring is installed in the correct direction. AS you look down at the trigger mechanism housing the spring should hook OVER the housing and UNDER the trigger bar/cruciform. I put one in backwards once and had the reset problems you are describing.

Thanks a lot. I'll look at that first thing in the morning.
 
From what I can see, the spring orientation is correct. Given that it's a full Zev trigger, I'm pretty sure it was all installed as a unit so not really a surprise now that I thought about it. So, back to the drawing board.
 
From what I can see, the spring orientation is correct. Given that it's a full Zev trigger, I'm pretty sure it was all installed as a unit so not really a surprise now that I thought about it. So, back to the drawing board.

Springs that are too light are imo #1 glock malfunction cause, is this a mixmaster special or a full agency build?
 
Striker spring is too light is my guess. Swap it to stock. Had a similar issue with the trigger reset. Went back to stock and problem was fixed

Zev striker springs are too light anyway.
 
Springs that are too light are imo #1 glock malfunction cause, is this a mixmaster special or a full agency build?

Hey Mike.

The frame is a Gen 3 that has the Zev sandpaper grip treatment, trigger guard undercut and finger grooves removed. It also has a full Zev trigger and stainless guide rod. Only the barrel is Agency. The one thing I'm not sure about is the striker and spring but I'll take that apart and investigate. I'll probably just put a stock striker spring in since that's cheap.
 
What is it running for a connector? I would honestly dump the zev trigger. Sell it and get an OC Custom with adjustable pre-travel. Go back to stock everything else, and then add stuff back in piece by piece until you find the culprit.
 
What is it running for a connector? I would honestly dump the zev trigger. Sell it and get an OC Custom with adjustable pre-travel. Go back to stock everything else, and then add stuff back in piece by piece until you find the culprit.

As I said, it's a full Zev trigger group. I'm going to replace the striker spring next.

How many rounds to date?

I've only put 150 or so through it. As I said though, I bought it used. I'm pretty sure the previous owner only put a few hundred through it.
 
I've only put 150 or so through it. As I said though, I bought it used. I'm pretty sure the previous owner only put a few hundred through it.
Ok, so it's a frankenglock... those are great (NO, really) but - quality parts aside, the tolerances need to line up. A Glock has all those parts in slow-mo contact and then fast for the reset. I've seen factory kit that is crisp as anything and quality aftermarket sets that just suck. I'd suggest a thorough cleaning with cleaner/degreaser, then lubing only the points Glock recommends, then racking and dry-firing like 500 times, clean again, and see if it works. All those mods and that finicky nature suggest to me a burr or obstruction. If that does not work, then, yeah, get a factory parts kit (cheap) and replace things until it works and adjust until you get it reliable with a trigger pull/break you like.
 
Yeah. Not a fan of Zev triggers or really messing with any springs in a Glock. Like Mike said, it's generally a recipe for disaster.... Even in Gucci Glocks that supposedly run 'good'.
 
Yeah. Not a fan of Zev triggers or really messing with any springs in a Glock. Like Mike said, it's generally a recipe for disaster.... Even in Gucci Glocks that supposedly run 'good'.

Never cared for all that modification. Some think they're pretty at barbecues, might squeeze some kind of advantage at competitions. But the real beauty in a Glock is the boring consistency.
 
the lighter striker spring can certainly cause light strikes but it shouldn't cause complete lack of trigger reset. when the slide comes forward into battery the striker should grab the sear (on a glock the rear of trigger bar). as the slides finishes going into battery the force of the recoil spring will overcome the force of firing pin spring and thus "cock" the striker rearward.

OP if your pistol is showing a dead trigger during live five, my guess is that the striker is not engaging the sear as the slide comes forward. there may be very little searing surface which is how these achieve such short trigger pulls. alternatively, if there is forward force on the trigger but still not reseting then i would focus on the disconnector.

when hand cycling the pistol you mention it resets. are you walking the slide forward? i would try releasing the slide and allowing the recoil spring to bring slide forward as if live firing. see if you can't reproduce the dead trigger. if the slide can be removed then you know the striker is missing or slipping off the sear. If you have access to a factory G17 gen 3 lower my guess is that your slide will work fine and the issue is probably on the trigger bar (i.e. lower) or less likely an out-of-spec striker.

i would inspect the trigger bar sear surface and the striker searing surface. see where they are showing some wear. if can't see then put sharpie on them and dry fire it. my guess is that only a small part of your trigger bar is engaging the striker.

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i have zero experience w gucci glocks. only bone stock with an occasional NY1 + 3.5# disconnector setup. there are folks on this forum who do gucci glocks and should be helpful. would consider posting on GT as well. could have Tim at G&N (Wrentham) look at the pistol. he can almost certainly sort it out for you. good luck.
 
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I have a G17 Gen 3 that has a Zev modified frame, Zev trigger and whatever else they offer as mods. For the slide, it has an Agency Arms barrel and, possibly, other mods but it's a stock Glock slide otherwise.

The malfunction is that the trigger fails to reset about 1/3 of the time. If I shoot, the slide cycles enough to load the next round but the trigger does not reset. If I manually cycle the slide, the trigger always resets.

Any thoughts on what the issue would be?


This kinda sounds like the disconnector isn't working.

If that's the case, there's a (small, but non-zero) chance of it going full-auto. (if the striker has enough mass and the primer is soft enough.
 
Going back to my above suggestion.

I would still say that the first thing to try is swapping to the stock Glock Striker Spring and then to the Stock Glock Trigger return spring.

I have tweaked a bunch of my glocks and one most recent issue was the failure to reset the trigger fully and was fixed going back to the Stock Glock Striker Spring.

I normally swap out the springs and my standard combination is the following

ZEV Firing Pin Plunger Spring
ZEV Trigger Return Spring
Wolff 5 Lb. Striker spring.
Stock Recoil Spring.

That is my normal spring formula for all my non carry glocks (i.e. competition guns).

The ZEV striker spring is way too weak IMHO. Leading to light strikes (which is why they sell the lightened Striker). I think (no info I can find on it, is its no more then 4.5 Lbs and might even be 4.0 Lbs. I'm not sure.

In addition to the above, the two heavily modified ones I have (G19 and G17), a Double Diamond 3.5# connector, Gen 3 Trigger bar with the smooth face trigger, ZEV Lightened Striker and the full .25 trigger job.

My G17 has at LEAST 13,000 rounds through it. And only two issues I have had were a broken connector (old style Double Diamond connector with the cut outs, failed at the cut out around 9-10,000 rounds) and I wore out a recoil spring.
 
Going back to my above suggestion.

I would still say that the first thing to try is swapping to the stock Glock Striker Spring and then to the Stock Glock Trigger return spring.

I have tweaked a bunch of my glocks and one most recent issue was the failure to reset the trigger fully and was fixed going back to the Stock Glock Striker Spring.

I normally swap out the springs and my standard combination is the following

ZEV Firing Pin Plunger Spring
ZEV Trigger Return Spring
Wolff 5 Lb. Striker spring.
Stock Recoil Spring.

That is my normal spring formula for all my non carry glocks (i.e. competition guns).

The ZEV striker spring is way too weak IMHO. Leading to light strikes (which is why they sell the lightened Striker). I think (no info I can find on it, is its no more then 4.5 Lbs and might even be 4.0 Lbs. I'm not sure.

In addition to the above, the two heavily modified ones I have (G19 and G17), a Double Diamond 3.5# connector, Gen 3 Trigger bar with the smooth face trigger, ZEV Lightened Striker and the full .25 trigger job.

My G17 has at LEAST 13,000 rounds through it. And only two issues I have had were a broken connector (old style Double Diamond connector with the cut outs, failed at the cut out around 9-10,000 rounds) and I wore out a recoil spring.


Wouldn't another solution to the light striker spring be a lighter trigger spring?

Granted, that's not the right way to do it...
 
Yes. A lighter (stock) Return spring will help and might be part of the full fix. But the first thing I’d swap is the striker spring. Then the return spring (along with the striker spring).

“I believe” the striker spring has more influence. But they do work together (actually opposite).
 
It has kind of already been said, but I'd just reinstall the stock parts. Let me ask you this; what has the gun gained from all the mods? Is it more accurate, more reliable, more....what? My gen 2 model 19 that i've owned since 1989 is just bone-stock other than some grip tape, and I honestly can't think of a thing that would make it better.
I'll admit that the trigger weirded me out at first. I competed with a 1911 for years prior to buying my Glock so anything other than a 4 pound, single-action trigger weirded me out. But after a few hundred rounds....ok, maybe a thousand, I got used to it. I've always felt that you're better off training yourself to succeed with your gun rather than reengineering it. But I'm sure the aftermarket parts manufacturers would strongly disagree with me!
 
OP is asking a technical, not idealogical question. we all agree stock glock offers optimal reliability, which is why I and many others don't modify them. however there's a huge market to turn glocks into race pistols. once someone has invested into such technology, the overwhelmingly popular suggestion of returning all parts to stock is - from a technical perspective - less than useful.

i've shot several of these gucci glocks and they can run FAST, so I certainly see the attraction. it just isn't my thing. hopefully some folk with actual experience on zev frame parts can chime in.
 
Just so I understand the problem correctly:

When it fails to reset the trigger, can you reset the trigger by pulling it forward? i.e. without touching the slide, pushing the trigger forward.

Can you get it to fail when dry firing? (i.e.: is there a slide speed component?)
 
Yeah. Not a fan of Zev triggers or really messing with any springs in a Glock. Like Mike said, it's generally a recipe for disaster.... Even in Gucci Glocks that supposedly run 'good'.

For the record, this was bought as a range toy and, again, because the price was too good to let go. I also hoped I'd find a Glock I really like (didn't work). I'm actually considering selling it (which cause isn't helped by this thread), but I want to make sure it's reasonably reliable first.

Just so I understand the problem correctly:

When it fails to reset the trigger, can you reset the trigger by pulling it forward? i.e. without touching the slide, pushing the trigger forward.

Can you get it to fail when dry firing? (i.e.: is there a slide speed component?)

No failures when I rack the slide manually and dry fire.

I haven't tried pulling the trigger forward manually, but that's something I'll try next time I'm at the range. What does that tell you if it does reset?

As for reinstalling the stock parts, those didn't come with it. I do have a Gen 4 34 (this is Gen 3) and I could rob parts off of that for testing, assuming they're compatible.
 
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