Gunsmithing Trouble Shooting Timney Trigger in AR15

[JTinIN]

The Timney trigger in a recent AR15 project with a Compass Lake upper is having issues after a 100 to 200 rounds, with the trigger not always working. After cleaning and a light lube it appears that the hammer is "sticking" in a lower position part of the time and you have to "wiggle" something (trigger, hammer with action open, safety) to get the hammer to pop into the correct location. Have tried removing the pistol grip, spring and safety detent, so the safety is loose, but does not effect the failure mode. Have an e-mail into customer service, friend had been single loading rounds on the bench, so the risk of a double was low ;-) and I will be tossing in a Rock River trigger for the time being, after trouble shooting is done.

Photos of Timney Trigger Issues

Any ideas on trouble shooting appreciated, if this is a known issue and/or other triggers to consider are all appreciated.

 

[19Scout77]

Re: Trouble Shooting Timney Trigger in AR15

When you tightened the two set screws that "wedge" the trigger into place (the ones with the half-threading visible in your pic above), how much torque did you use (alot or a little or somewhere in between).

I could see this happening if you did not tighten them enough as the trigger assembly will move around. Looking at your pictures, it apears that the heads of the screws are visible. If they are you may have found your problem. When I tightened them down in my trigger, they were not visible.

 

[JTinIN]

Re: Trouble Shooting Timney Trigger in AR15

I tighten the screws "a lot" for there size. The screws which are visible four threads down, are the second screw on top, which is use to lock the bottom screw. The pins are still tight and don't observe any play in the trigger body with respect to the receiver.

Thanks for the idea will keep watch if the bottom screw is tight on each side when I am taking everything apart to trouble shot / replace / return.

 

[JTinIN]

Re: Trouble Shooting Timney Trigger in AR15

Well 10AM this morning got a reply back from Timney Trigger offering to upgrade to a new model if I would sent it back .. not bad for an e-mail sent over a 3 day weekend.

 

[coast2coast]

Re: Trouble Shooting Timney Trigger in AR15

New model as in new version or new replacement? Has there been a recent design change?

 

[JTinIN]

Re: Trouble Shooting Timney Trigger in AR15

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: coast2coast</div><div class="ubbcode-body">New model as in new version or new replacement? Has there been a recent design change? </div></div>

I might just have gotten new old stock, vs a recent design change. However, after seeing photos, the following reply indicates to me that there maybe an improved trigger coming back in the mail. Which is why I sent it in vs adjusting the disconnector, which appears to be the issue, after I took out the trigger.

"You have an older vintage of our trigger and I know you will be very happy with the upgrade"

 

[sandwarrior]

Re: Trouble Shooting Timney Trigger in AR15

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: JTinIN</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: coast2coast</div><div class="ubbcode-body">New model as in new version or new replacement? Has there been a recent design change? </div></div>

I might just have gotten new old stock, vs a recent design change. However, after seeing photos, the following reply indicates to me that there maybe an improved trigger coming back in the mail. Which is why I sent it in vs adjusting the disconnector, which appears to be the issue, after I took out the trigger.

"You have an older vintage of our trigger and I know you will be very happy with the upgrade"</div></div>

That is good. When I was looking at your troubleshooting photos I noted the first one was hammer 'stuck down'. I could see a burr like that catching and holding it down. But, when I look at it and see the pivot point I'm not thinking so. To me, it is as you said, the problem is with the disconnect arm needing adjustment. I'm still trying to figure out what is causing or caused that burr. The part of the spring behind the hammer comes down, but the burr part rotates away from it. The spring coils tighten and should tighten up around the pin therefore pulling them away from it too. The only thing I could think of then is if the spring comes out and hits it when the hammer is released?

Anyhow, let us know what the new one looks like.

 

[JTinIN]

Re: Trouble Shooting Timney Trigger in AR15

Just received the tracking notice, trigger will be back late this week. Will see about posting photos if anything of interest.