Browse Categories
Shopping Cart
Your cart is empty.

Northwood Trigger Installation Guide

Kel-Tec PF-9

CAUTION!  Please review this guide completely before purchasing your upgrade kit!

 




Kit Contents:

 Trigger (ATPF9T or ATPF9A)*

  • Trigger Pin, Stainless (photo shows older-style, modified factory pin)
  • Set Screw 6-32 x 3/16”, Stainless, w/yellow or red Loctite Patch
  • 2mm Pin Punch
  • 3mm Pin Punch
  • 1/16” Allen Hex Key

Page



PLEASE BE SAFE!!

Make sure your firearm is unloaded. Follow all safety guidelines in your owner’s manual when handling your firearm.

NOTE:  Once installed, the trigger may still need proper fitting for your firearm to function. The trigger contact surfaces or grip cutout may need to be filed or sanded to obtain the proper clearances required.


Tools and Items Needed: 

Standard gun cleaning materials and lubes

Small hammer

Gun mat or soft working surface

Small wood blocks (2) same size

1/8” Pin Punch (available at hardware store)

Q-Tips

Flat Blade Screwdriver (medium with long shank)

“Bic” Pen or short ¼” wood dowel

Round files, small and medium

Sandpaper, medium to fine grit


*  Either PF-9 or P-11 may be used for illustration unless the procedure is model-specific.


Disassembly


IMPORTANT: Inspect the gun carefully, while performing these steps, and replace any worn or cracked components before attempting this installation.


Start by field stripping the pistol. You will be working only with the grip/frame assembly. Once the slide assembly and magazine are set aside, begin with the frame removal.

 

Support the pistol on its side between two blocks of wood, books, or on a cartridge rack, and with a 1/8” pin punch and small hammer, tap out the three frame pins, as shown. (If your frame pins look larger on one side, tap them out from the smaller side.)

With the pistol in one hand, hold rearward pressure on the hammer with your finger while slowly pulling the trigger. Once hammer is released, allow it to rotate fully forward.

 


Page 2


Place the pistol upside down on a “friendly” surface like a gun mat. With a cleaning patch or folded cloth to protect the front of the grip, insert a flat bladed screwdriver under the hammer spring retainer.

 

Pry up slightly on the hammer spring retainer until it clears the recess, and slide it toward you with your thumb. Let it down gently into the magazine well with the screwdriver.

 

Using the slide as a lever, gently begin lifting the front of the frame out of the grip until the trigger components are visible on the sides of the frame. Do not lift the frame out of the grip just yet.

 

Remove the slide from the frame, and set aside.

 

CAREFUL! There are components on both sides of the frame that will fly away unless you hold your fingers along the sides as you pull upward.

 

IDEA: Remove the frame from the grip with both hands inside a gallon size zip-lock bag to catch parts if they come loose.

 



Page 3


 

As you pull the frame clear from the grip, the hammer spring and retainer will come with it, and will dangle from the frame. Leave them attached for now. Keep holding the left and right frame components to the frame as you remove it from the grip. The trigger bar on the right side is spring loaded.

 

Set the grip assembly aside.

 

Turning the frame over…

 

While holding the trigger bar on the right side, turn the frame over. The left side components are the slide stop lever and spring. The spring sits on a nub in a circular cutout with the lower end riding in a very thin slot on top of the slide stop lever.

 

While still holding pressure on the right side (trigger bar), carefully release the slide stop lever and spring – and lift them away from the frame.

 

Set the slide stop lever and spring aside for now.

 


Page 4


 

Turn the frame assembly over to the right side.

 

Note the trigger spring “tab” positioned in the trigger bar slot. While holding down the front end of the trigger bar, carefully lift the larger end slightly, away from the hammer axis (pin).

 

Rotate the trigger bar clockwise, allowing the trigger spring to unwind out of the slot in the bottom of the trigger bar.

 

The trigger spring will not fly away, but it may sting your finger if it slips out of its groove prematurely.

 

Set the trigger bar aside.

 

Page 5



 

Trigger Removal

 
Place the frame across two blocks, allowing the hammer spring/retainer and the trigger to dangle underneath.

 

Looking down at the top of the frame with the trigger fully forward in the reset position, you will see the top of the trigger pin aligned with the small access hole in the top of the frame where the barrel normally sits.

 

Notice the angle of the pin in relation to the frame. Using the 2mm small punch provided, (or small end of the “combo” punch on older kits)*, position it through the hole in the frame, onto the trigger pin at the same angle as the pin. Steady the frame with your hand as you hold the punch in position. CAREFULLY tap the pin until it pushes out the bottom of the plastic trigger. Save this pin. Your trigger may come out with the pin if it was cracked at the top, prior to this procedure. A replacement trigger should be ordered from Kel-Tec as a spare.

*A 3/32” drift punch (shown) can be used, but the 2mm will penetrate the trigger more easily.

NOTE: The newer PF-9 uses a “barbed” trigger pin, and it might be extremely difficult to remove. CAUTION – Do not tap too hard on a stubborn pin that won’t budge. You can easily damage your trigger axis, or more importantly, your aluminum frame! Kel-Tec has said that the plastic trigger on newer guns may need to be “snipped out.”

Using a pair of diagonal pliers, snip away the plastic trigger from around the pin. Then grab the head with a pair of pliers, gave the pin a slight twist and pull it out gently.

If you are not comfortable doing this, seek help from a qualified gunsmith.

 

Remove the trigger spring from the right side of the trigger axis, and set aside. 



Page 6


 

Gently push out the trigger axis from the left side of the frame with the punch, and set aside.

 The stock trigger can then be removed from the frame. Save this trigger and original trigger pin for any future shipments to the manufacturer for service work. Kel-Tec would normally return your firearm to its original factory condition, and your aluminum trigger could get misplaced.

 

Finish cleaning any remaining oil or grease from the frame and trigger cutout area.

 

Remove the hammer/spring assembly from the frame by pushing out the hammer axis.

 
Set these aside for now.

Important: Removing this assembly expedites the frame/grip clearances later without having to attach the grip assembly.

 

***

Page 7




Trigger Installation

 "Hybrid" trigger-specific installation steps will be directed to the Hybrid Trigger Supplement (link at left). Directions back to the next step in this Trigger Guide will be provided there.

The aluminum trigger will be installed much the same as the stock trigger with a few exceptions. The factory trigger pin is “barbed” so that it will not work loose from the plastic trigger. The replacement pin has been trimmed to provide a snug fit in the aluminum trigger. A Nyloc or Loctite-coated setscrew will also provide a mechanical “lock” for the new trigger pin.

 
We will use gun grease instead of oil initially on the trigger, axis and frame. Once the gun is operational, oil can then be used on these parts during regular maintenance through the top frame access hole. (See “Firearm Lubrication” at GoldenLoki.com)

 

 

Before beginning, make sure that the trigger axis (Page 9, Figure 1) will fit inside the large hole in the aluminum trigger. It should be a snug fit. Do not sand if possible.

 

Apply a thin coat of gun grease to the sides of the trigger around the larger ¼” axis hole. Also apply a thin coat inside the hole.

Carefully position the trigger into the frame, aligned with the axis hole.



Page 8


 

Apply a thin film of gun grease to the pivot surfaces of the trigger axis.

Insert the axis through the frame and trigger.


"Hybrid"
triggers - go to Hybrid Trigger Supplement: "First Pass"




Axis Tab Clearance Checks

 Line up the holes in the trigger and axis (use the included 2mm punch or small end of the combo punch if necessary.) Temporarily insert the new trigger pin through both components.

This should be a snug fit. If you can’t push the pin in by hand, try to rotate it until it goes all the way in.

 

Do not sand or file the pin.



Page 9



Turn the frame upside down on a wooden block. Make sure that the ejector hangs off the edge of the block.

With the frame upside down, finish seating the trigger pin by placing the 3mm large punch (or large end of the combination punch on older kits) onto the pin, and tapping it very lightly with the end of a screwdriver handle.

(DO NOT use the 2mm punch, or small end of the combo punch, as it may deform the head of the pin)

 IMPORTANT: The head of the pin must be seated completely into the countersunk hole.

(see Page 13, Figure 1)

 

Access Hole Check

 

 

Looking down at the access hole in the top of the frame, make sure that the end of the trigger pin is FLUSH with the top of the trigger. It cannot protrude more than 1/32” or it will jam in the frame. If this is the case, remove and trim the end of the pin with sandpaper or a small file until it fits properly.


Page 10


With the trigger in the full rearward position, there should be little or no gap between the front of the axis tab and the frame cutout.

Any gap should be made VERY small to allow for over-travel after the trigger break. Too much gap will result in the hammer not releasing.

Note: The new ATPF9T and ATPF9A triggers are engineered to fit with little or NO gap.

When filing or sanding the trigger to increase over-travel, try to keep some gap here if possible.

Grip Cutout Clearance Checks

 

Insert the frame with the trigger temporarily installed into the grip. Starting at the front of the grip, line up the frame pinhole, and then lower the rear of the frame into the grip. Press the frame into the grip until the frame pinholes all line up.

At full rearward, your trigger should stop in this position.


Page 11

The trigger must clear the back of the grip cutout, and contact the inside of the frame cutout just above it.

If the trigger travels freely without interference, skip to bottom of page.

If the trigger rubs or feels like it drags on any part of the grip, locate the source of the interference. Remove the frame from the grip, and trim the grip (next step).

 

Grip Modification

If your trigger contacts the plastic grip cutout in any way before reaching the aluminum frame cutout, remove the frame/trigger assembly from the grip.

Use a piece of #280 grit sandpaper rolled around a “BIC” pen or similar cylindrical object to remove a bit of this edge and re-assemble to check.

Repeat this process until the trigger clears the plastic grip cutout.

 


Trigger Final Assembly


Remove the frame from the grip, and set the grip aside.

"Hybrid" triggers - remove setscrew prior to next step.


Line up the top of the trigger pin with the access hole in the frame. Using the 2mm punch (or the small end of the combo punch), push the trigger pin back out about half way until you can see the end just protruding into the center of the axis.

Page 12


 

Insert the trigger spring into the axis with the “arm” pointing toward the front of the frame, and the “hoop” positioned so the trigger pin will pass through it.

 


"Hybrid"
triggers - go to Hybrid Trigger Supplement: "Second Pass"




 

While pushing down on the trigger spring, push the trigger pin into the trigger. This should be a tight fit, so you might have to wiggle the alignment or twist the pin slightly to get it in.

 IMPORTANT: Keep firm downward pressure on the spring with the “arm” of the spring in the position shown, or the trigger pin may hang up on the small hoop at the end of the spring.

 Using the large end of the small punch, PUSH the pin all the way into the hole.

 

Turn the frame upside down on a wooden block. Make sure that the ejector hangs off the edge of the block.


Page 13


 

With the frame upside down, finish seating the trigger pin by placing the 3mm punch (or large end of the combo punch) onto the pin, and tapping it lightly with the end of a screwdriver handle. DO NOT use the small end of the combo punch, or 2mm punch, as it may deform the head of the pin, and drive it too far into the trigger!

IMPORTANT: DO NOT skip this step! The head of the pin must be seated completely up inside the countersunk hole. (Page 12, Figure 1)

Check that the top of the pin is flush with the top of the trigger, by viewing through the access hole in the top of the frame. (Page 10, Figure 3)

 

Make sure the setscrew hole is clean and free of debris or oil. Start the provided #6-32 stainless setscrew into the threaded hole at the front saddle of the trigger. Notice that there is a patch of yellow or red Loctite on the setscrew threads. This is designed for a few installs before the coating loses its locking capability. Heat is not needed to loosen yellow Loctite.

 Blue Loctite #242 can be used if the coating wears off from repeated use. Apply a small drop with a toothpick. Heat is needed to loosen red or blue Loctite to remove the setscrew. A butane lighter or heat gun will provide sufficient heat.

 

Run the setscrew down onto the trigger pin using the included 1/16” allen wrench (not shown). There will be resistance from the Locktite patch, but it will still go in smoothly until it firmly contacts the trigger pin. DO NOT OVER-TIGHTEN! A snug fit is all that is needed. (For technical types – a #6-32 screw in aluminum is suggested to be 5.3 inch-pounds of torque).
Check that the  trigger pin is locked by pushing on it with the small punch from the top access hole.

Careful! If you strip out the allen socket hole in the setscrew, do not try to hammer the trigger pin back out past the setscrew, or you may damage the axis hole in the frame. Contact Northwood for assistance.

 



Page 14


 

Re-Install Hammer


Place a drop of gun oil both on the hammer axis, and both sides of the thicker section of the hammer. Insert these components into the frame. The hammer axis should go in easily.

 

***

 

 

 Frame Re-Assembly


First, make sure that the trigger moves freely in the frame. You may feel a slight drag from the trigger spring arm rubbing the frame. Once the spring is positioned into the trigger bar slot, this will no longer be a factor.

 

 

Lubrication:

 

On the right side of the frame, lightly apply gun grease to the area under the trigger axis, and to the top of the axis around the trigger arm nub.

 

Apply a thin coat of grease to the rear frame around the hammer axis pin area.



Page 15


 

Apply a thin coat of grease to the frame side of the slide stop.

 

Apply grease to the spring slot along the top edge.

 

Set aside.

 

 

Apply a thin coat of grease to the “frame” side of the trigger bar.

 

Apply grease to the spring slot along the bottom edge of the bar.

 

On the right side of the frame, place the trigger bar over the nub on the trigger axis at the front end, and the hammer axis on the rear end. (The small tab at the rear of the trigger bar will point inward.) Apply a light coat of grease to the trigger bar.


Page 16


 

Grasping the frame and trigger bar with one hand, hook the trigger spring with a plastic ballpoint pen cap, or your fingernail, and carefully turn the spring counter-clockwise over the trigger bar, and into the slot on the bottom of the bar.

Hold this assembly with a thumb or finger, as the trigger bar will fly away and spread grease everywhere.

Turning the frame over, (and while still holding the trigger bar in place), install the slide stop lever onto the lower nub of the frame with the tab positioned in its hole as shown.

 

Apply a small amount of grease to the frame where the long end of the spring will set.

 



Page 17


 

Place the slide stop spring onto the upper nub cutout with the long side toward the top. Again with your pen cap or fingernail, pull the short side of the spring back into the greased slot in the top of the lever.

 

Spread a thin film of grease over this area.

 

While holding the right and left components against the frame, lower the hammer spring retainer and spring into the grip, and insert the front of the frame into the grip. As the frame assembly moves down into the grip, you may need to pull back on the trigger slightly to clear the cutout.

 

VERY IMPORTANT!!

With the front of the frame down as far as it will go into the grip, position the rear of the frame about ½ inch above the back of the grip.

Make sure the hammer axis pin is centered, or it will hang on one side.

The rear of the frame has to be high enough to push the hammer block forward (next steps).


Page 18


 

Setting the Hammer Block

 

With your left index finger, pull up on the front of the hammer, rotate it all the way to the rear of the frame, and hold it there.

 

Locate the hammer block just inside the grip and below the frame.

Using the plastic ink tube from your “BIC” pen, position it as shown into the notch on the right side of the hammer block.

Holding the frame with ONE hand, push the hammer block fully forward with the plastic tube. If it will not go forward at least ½ inch, raise the frame a bit more until it clears under the hammer.

 

As you hold the hammer block forward, press the frame down on top of the plastic tube. Keep pressing down as you pull the tube back out, and the frame will seat fully into the rear of the grip.


Page 19


 

Seat the frame assembly into the grip. If it seems stuck, pull the trigger slightly to clear the grip cutout.

 

All three of the frame pin holes should line up, but do not install the frame pins yet.


Note: When resetting the Hammer Spring in the next step, the hammer should be in the RELEASED position, as shown on Page 2, in Fig 2. In the same way it was done for disassembly, with the pistol in one hand, hold rearward pressure on the hammer with your finger while slowly pulling the trigger. Once hammer is released, allow it to rotate fully forward.

Place the assembled components upside down on a “friendly surface.” With a folded patch to protect the grip, reach down inside the magazine well with the flat-bladed screwdriver and pry up on the hammer spring retainer.

While prying upward, guide the retainer with your other hand, pushing it up and back until it snaps into its recessed slot.


Page 20


 

Clearance Checks


Hold the top of the hammer from moving forward with one hand (use a pad for your finger), and slowly pull the trigger. Find the spot where the trigger “breaks”, and note how much free “over-travel” there is before the trigger contacts the frame. (See below)

If hammer does not release, go back to make sure steps on Page 12 and Page 19 have been done correctly.

Over-Travel Check


You MUST have at least 1/8” free travel (over-travel measured at the tip of the trigger) remaining after the hammer release.

 

If the trigger does not release the hammer before reaching the 1/8” free-travel mark, STOP. The trigger may need to be trimmed slightly. (See Page 22)

 

Pre-Travel Check


Pull the hammer back to the “cocked” position. You MUST have at least 1/8” of free travel (pre-travel measured at the tip of the trigger) from the reset position, before the hammer begins the cocking sequence.

If the trigger does not reset before reaching the 1/8” free-travel mark, STOP. The plastic grip opening may need to be trimmed away slightly. (Pg 23)

 

 Page 21





Trigger/Grip Modifications

The latest version triggers are designed to work without modification in most PF-9, P-11 and P-40 firearms. If for some reason, your trigger will not work as advertised, PLEASE contact pops10@northwoodcomp.com before attempting to modify your trigger. If you are not comfortable doing your own modifications, your trigger can be returned for a full refund, provided it is still in its original unmodified condition. Use the "Contact Us" link above to request our current shipping address for returns.

 

Too little over-travel (or hammer may not be releasing)


The adjustment needed to increase over-travel after the hammer release is to remove material along the cylindrical back “spine” of the trigger. This can easily be done with #280-#400 grit sandpaper.
(No returns will be accepted if custom fitting has been performed.) Please email Northwood Components for technical assistance with this procedure.
Tip: Before removing trigger for trimming, "paint" the back surface lightly with gun grease. Pull the trigger back into the frame to see where it is making contact. This will be the area that needs sanding.

 

Remove the frame/trigger assembly from the grip, and remove the trigger from the frame. (Pages 2 through 7)

Keeping the same angle as the machine cut at all times, sand or file evenly around the back surface, removing only a small amount of material at a time. This is best done with the trigger out of the frame for better control on keeping the angle constant, and a cylindrical surface.

Frame and grip assembly can be assembled without grease to re-check for adequate over-travel clearance. When trigger is trimmed sufficiently, begin again at Page 8 using gun grease for final assembly.

 

When sanding and removing material, try to maintain a small “gap” between the trigger axis and the front edge of the frame pocket (as pictured earlier). Check progress by assembling these parts (Page 8 thru 20) without grease, and testing until sufficient clearance is achieved. The gap can be almost non-existent, as long as the trigger contacts the frame at the same time. Maintaining even a minimal gap will relieve undue torque on the trigger pin when firing.

 

Note: The new ATPF9T and ATPF9A triggers are engineered to fit with little or NO gap.

 

 

Page 22




Not Enough Pre-Travel (or hammer may not be resetting)

 

Symptom: Trigger may not reset, or hammer will not cock with slide installed.

 

The adjustment needed to increase pre-travel (free travel prior to beginning the hammer cocking sequence) is to remove a small amount of material from the front of the grip cutout. This can be done with sandpaper rolled around a “Bic” pen or similar small wood dowel. Determine, if possible, where and how much material needs to be trimmed, and remove enough to allow 1/8” of free travel.

More grip material can be removed without adversely affecting the action. But because this will increase pre-travel, the finger space ahead of the trigger will also decrease, and the upper “pinch protection” may also diminish somewhat. If desired, the grip can be trimmed until the trigger totally clears the grip. The trigger will then stop against the frame, or the axis tab will stop against the internal frame pocket, as it did with the stock trigger.

 

Remove the frame/trigger assembly from the grip. (Page 2 through Page 4) Set the (greased) trigger / frame assembly and side components aside.

Only a small amount of sanding should be required on the forward edge of the grip opening to allow sufficient trigger travel to reset. Remove only 1/32” – 1/16” at a time. (1/16” removed from the grip edge will allow more than 1/8” travel at the trigger tip.) Contour the grip edge to match the trigger bump.

Re-assemble the frame components into the grip (Page 16), re-position the hammer spring retainer, and test the trigger reset.

 Page 23




Final Assembly

                                                                                                                                                              

 

 

 

Once the hammer release function, trigger reset function, and minimum clearances have been established, and the trigger moves freely, continue with completing the frame assembly:

 

Install the three frame pins into the grip and frame, tapping lightly with the screwdriver handle.

 

 

If you are satisfied with the fit and operation of the trigger, then lube and assemble the remaining firearm components, and wipe down. Check the firearm for proper operation.


Note: If after installing the slide, the trigger will not engage the hammer, then disassemble, and go back through the steps on Page 23. With the hammer cocked, make SURE that the trigger is traveling freely at least 1/8” before it begins to cock the hammer. If not, you WILL need to sand down more material from the front edge of the trigger cutout in the grip.

 ***

 

Remember: To dry fire the PF-9, there MUST be a snap cap in the chamber.

 

 **  If you are not happy with the trigger for any reason, please contact pops10@northwoodcomp.com for our current return address, and a full refund. The trigger must be in its original, unmodified condition. No returns will be accepted if they have been sanded, filed, polished, or otherwise modified in any way.

IMPORTANT:  These parts may require a significant level of mechanical skill to install.  We do not recommend purchasing replacement or upgrade parts if you have little or no experience with firearm components.  If problems occur with your firearm due to improper replacement or assembly of a part, repairs may not be covered under its warranty.  A gunsmith may be able to correct any issues if the weapon is sent in to them, however shipping costs must be covered as well as any replacement parts needed due to improper assembly.  These parts are available to qualified owners that prefer to replace or install parts on their own rather than send the weapon in for upgrades or service work.  This guide is intended for those with the knowledge and experience to make these replacements.

Agreement: Northwood Components, LLC shall not be responsible for any changes made to your firearm by you or any other party. NORTHWOOD COMPONENTS, LLC WILL NOT BE LIABLE FOR ANY DAMAGE OR INJURY OCCURRING TO YOU, OR ANY OTHER PERSON, OR TO ANY PERSONAL PROPERTY WHATSOEVER RESULTING FROM THE INSTALLATION OR USE OF THIS PRODUCT. Purchaser agrees that they have read and understand the trigger installation process described in the Aluminum Trigger Guide. Purchaser agrees to protect, indemnify, and hold Northwood Components LLC, it’s owners and assigns harmless from and against any and all loss, costs, expenses damage or liability arising out of any accident or other occurrence while installing or using this product causing injury to any person or property.


For a copy of this document, right-click and "Save As..." a Web Archive or a Complete Web Page.
You can then view it offline, save as a PDF file, or print.


This guide has undergone extensive revisions, and has been approved by Skunkworks Beta Test Group for trigger installation.

 

 

Copyright © 2012-2016 Northwood Components

Rev 23G

Page 24