I got my first AR as a gift awhile back. Being a gift and a suprise. There were a couple of changes i wanted to make. So i went to dissembling it. I noticed the takedown pins were very tight, hard to remove so i hammered them out, the rear pin came all the way out, it looks like the detent was not in the groove of the pin. maybe why the pin was so hard to remove. Anyway, now i have a problem. The detent has closed up and i cant figure out a way to get the pin back in.

This appears to be a different setup than most.(from what i can see online, im no expert) The detent is actually inside of the hole that the takedown pin goes into, ive made every effort push the detent down and slip the pin in but havent had any luck. I know theres gotta be an easier way that im not thinking of.

Any ideas?

Welcome to the fray.

Stick the flat end of a quarter-inch drill bit through the TD pin hole from the receiver's left side; push the detent back against the spring until the bit goes fully through; use the takedown pin to push out the bit.

Normally, the takedown pin can't be pushed out of the receiver, once installed. Are you sure the TD pin isn't damaged?  Never mind. I re-read and see that you said the TD pin wasn't aligned right, and the detent wasn't in the groove. Whoever assembled that lower should be lead away from the work bench and given a sternly-worded lecture about quality control.....and maybe a couple days off without pay.

I just tap it out with punch when new. Grease it and it will loosen up with use.

Sometimes the front pin will come out easier and once it's pushed clear it will release pressure on the rear. I would prefer tight pins to loose.

The problem is that I can't get anything in the pin hole because the detent is in the way. Through hours of meditation I've figured out that I need to completely remove the detent and reinstall the takedown pin and detent the correct way this time.

I think you guys misunderstood my problem lol it's all good though I know I'm not the best at explaining myself as far as ARs go. But I believe I've solved the problem, now just gotta wait until I can get an armorers tool so I can get that detent out

Do you have a wrench for the castle nut?



If you back off the castle nut, allowing the rear end plate to move back a bit on the buffer tube, you'll take the pressure off the Take Down Pin spring and the detent.   Then replace the take down pin, push the end plate back into position (careful to make sure the spring doesn't get bent going back in), and re-tighten the castle nut.

A photo might be helpful.

This.  I really don't know how else you can do it other than backing off the castle nut, pulling back on the receiver end plate, and relieving spring tension on the takedown detent.  Do this and you can slide the pin back in, tighten everything up, and be good to go.

Here's a vid that shows what you are dealing with.
Welcome to BRD.

I'd say you deformed the detent plunger when you hammered the pin out so now it can't go back into it's bore.

Dental picks or a Linoleum Cutter might work.

Well I've reinstalled the pin and detent after getting my castle nut wrench today, but unfortunately that didn't fix the problem. The pin can still come all the way out. Since the parts are cheap I'll just buy new extended pins, spring and detent. Should fix the problem, it may be that the detent is deformed, the pin is very hard to push in and take out.

Based on what you're saying, you have an out of spec part.  As you now know, the pin shouldn't come out if the detent is riding in the channel on the pin.

Hopefully the new detent fixes it, but don't be surprised if you need a new pin.