Lower Receiver Assembly (AR-9, AR-15, and AR-10/LR108)
Step L8: Takedown Pin Installation
Objective: In Step L8 of lower receiver assembly, we will install the takedown pin onto the lower receiver.
Tools Required
Components Required
| Quantity | Component |
|---|---|
| 1 | Lower Receiver |
| 1 | Takedown Pin |
| 1 | Pivot/Takedown Detent |
| 1 | Pivot/Takedown Spring |
Instructions:
NOTE: If you are building an AR-10 on the Aero Precision M5 platform, you will need to install the takedown pin assembly before you install the pistol grip, as the detent cavity is oriented from the bottom instead of from the rear.
Step L8.0: Remove Existing Takedown Pin (replacement/upgrade only)
If you are replacing your existing takedown pin (or need to remove the takedown pin for any other reason), first ensure the firearm is unloaded.
Before you continue, you will need to remove any components that are securing the pivot/takedown detent and spring for the takedown pin. For AR-15s and AR-9s, you will need to remove the buttstock and (for carbines) loosen the receiver extension castle nut. For AR-10s (on M5 platform), you will need to remove the pistol grip.
With the receiver extension end plate (or pistol grip) out of the way, the pivot/takedown spring and detent should fall out of the lower receiver when stood upright. The takedown pin can then be removed from the lower receiver.
Step L8.1: Lubricate the Takedown Detent Cavity
Add one drop of wet lube to the detent cavity using a needle dropper.
Step L8.2: Lubricate the Takedown Pin Shaft
Wipe a light coat of wet lubricant over the shaft of the pivot pin.
Step L8.3: Insert the Takedown Pin
Insert the takedown pin into the lower receiver. Be sure to orient the groove in the takedown pin appropriately (to the rear of the lower receiver for AR-15 and AR-9; downward for AR-10 on M5 platform).
Step L8.4: Insert the Pivot/Takedown Spring and Detent
NOTE: For the AR-15 and AR-9, the detent and spring will be fed into the lower receiver from the rear of the lower receiver. For the AR-10 (using the Aero Precision M5 platform), the detent and spring will be fed into the Lower Receiver from the bottom of the lower receiver.
Insert the pivot/takedown detent into the cavity of the lower receiver.
Insert the pivot/takedown spring behind the detent.
If you are building an AR-15 or AR-9, proceed immediately to Step L9 (installation of the receiver extension).
If you are building an AR-10, proceed immediately to Step L7 (installation of the pistol grip).