I need some tips on that fron pivot detent and spring. I'm not kidding you when I say I tried for 30 minutes this afternoon to get it in and it just kept popping off, until finally I managed to destroy the spring. I geuss I have to go buy a Bic lighter tommorow. But are there any tricks to getting in in there?

I think I used a razor blade to hold the detent in.  I can't remember, as it's been a while since my last build.

feeler gauges from home depot make it very easy.

I had actually made a tool with an old gutter nail that I drilled a hole through, then polished. It works great. I have the actual tool now, but I have only used it twice. My home made tool has been used 5 times and will be used on my next build.

I use a pivot pin installation tool. #27 about 2/3rds down this page.

I used an allen wrench to hold the detent down on all my builds.  It helps to have a second person for this job.

I used a small flat blade screwdriver that's just small enough to hold it in with pressure from the left side so I can slide the pivot pin in from the right.  Also, take a towel and wad it up and place it in front of the lower so when the detent goes flying it flies into the towel!

Quoted: I use a pivot pin installation tool. #27 about 2/3rds down this page.

I've used that tool, but I find a thin pocket knife like those Swiss Army knifes you find on key chains to work better.

Buy a 1/4" hinge pin at rhe hardware store . It does the same job as the pivot pin too @ 1/5 the cost.

I've learned to do it without an extra tool, but I do the pin installation inside a gallon size clear freezer bag.  That way the escaping spring is not lost.

I've never understood why so many people have trouble with this.

It takes me about 20 seconds to install the pivot pin (and that includes dipping a pipe cleaner in clp and swabbing out the hole first to make sure it's clean).

-insert the spring (yes, I'm using the correct spring)

-insert the detent pin

-hold the pin (sleightly depressed) with your left thumb and index finger

-with the pivot pin in your right hand, use it to depress the detent the rest of the way (keep your thumb and index finger there to keep the spring and detent from launching), insert the pivot pin

-move it in and out a few times to make sure the it works properly


For me, this part of the build is really simple.

I have more trouble with the damn trigger guard roll pin...

For the Original Poster:

Make sure your hole is clean.

The spring should be all the way inside the hole. I'm kinda confused on how you ruined the spring.. ? If anything, you should have lost the detent pin and spring..

It might help you if you do the assembly inside of a large zip lock bag. That way if you launch anything, it won't go very far.


Good luck,

Gene

Gene,

Thanks for the advice. This is my very first build. Everything went smooth besides this. The roll pin for the bolt catch was a booger too, but I eventually got it.

The way a fubar'd my spring was I was sliding the pivot pin in over the spring and detent and almost had it in when the detent shot off (into my duffle bag I was using for that purpose) and the pin slammed foward locking the spring inside the cup on the pin. The only way to remove the pin was to rotate it which of course stretched the spring flat. But I hear you can get those springs out of BIC lighters so I'm going to try it again today.

I didn't even think about cleaning the hole, I will surely do that. Thanks!

Yes I had the same type problems, bend two springs lost detents.

Now I do like the above poster, I use the largest allen wrench that will slide through the front takedown hole.  I put in the spring, press detent down with finger nail and hold, then slide the allen wrench through to hold it in place.  Then I take the takedown pin and push it against the allen wrench(while holding the allen wrench with my left hand and keeping pressure against it) and slide it over.  I did my last four lowers with this method and each one took less than a minute.

I did try the screwdriver before this and made it work but not nearly as easy or fast as the allen wrench method.

I put together a AR15 yesterday and here's how I got the detent and spring for the front take dow pin in.

I inserted a 1/4 drill bit shank in the opposite side that the pen is inserted.

Take a small pair of neddle nose pliers to hold the detent.  

Press the detent in with a 3/32 nail set. (The nail set is cupped on the end preventing the detent from slipping out and shooting across the room.)

Press detent in until flush with surface.

Slide drill bit shank over, pushing nail set out of way.

Detent is now held dow by drill bit shank.

Using front take down pin, push drill bit shank back out.  

Rotate front take down pin.

Detent now istalled.

It took longer to type this than it did to actually accomplish the pin instulation.

Thanks guys. I used the allen wrench trick and it took me one try and all of 10 seconds to do. I used the spring from a small Bic lighter to replace my spring, worked perfect!

Quoted: I used a small flat blade screwdriver that's just small enough to hold it in with pressure from the left side so I can slide the pivot pin in from the right.  Also, take a towel and wad it up and place it in front of the lower so when the detent goes flying it flies into the towel!

Same here...I use a jewelers screwdriver that is narrow enough to fit in the slot on the pin.

Once I have the detent captured, I use the pin to over the driver blade then withdraw the driver...push the pin in.

I have a shoe box on edge on my bench to catch the detent if it gets away.

I made this tool and it works great

Here's what I use:



1/4" clevis pin and whatever sized allen wrench to fit through the holes.



Slide the pin through the ears from the left side. Line up the holes and drop the spring and detent pin into place.

Use the allen wrench to push the spring and detent through the clevis pin and rotate 90° as shown.



Use your pivot pin to push the clevis pin out. As I do this I point the receiver down towards the red shop rag. The rag has always been enough to capture an errant detent pin if I don't do it right the first time. And usually I don't. But I also don't have to try more than two or three times before I get it right.

The razor blade trick works every time and does not require some fancy tool.

+ 1 on clevis pin -  .50 cents at local hardware store

I just put a business card over the pivot pin hole to keep the detent from falling that way. Then use the pivot pin to push the detent down into its hole. Remove the business card and push the pin into the hole. Quick and Easy!