16ga.com Forum Index
Author Message
<  16ga. Guns  ~  Marlin 90 / Ranger 103 Disassembly tutorial
thunderstick
PostPosted: Thu Apr 11, 2019 8:27 am  Reply with quote



Joined: 23 Jun 2005
Posts: 185
Location: Boulder,Colorado

Ranger 103 / Marlin 90 Disassembly & Reassembly
This is the general procedure I followed to disassemble my recently acquired Ranger 103 ( in 16 ga). The gun had two issues which I hoped could be rectified: Very heavy triggers and a safety that was so hard to move on / off that it practically took the skin off my thumb. I give a huge THANK YOU to Nick Hammack, an acknowledged expert on these shotguns, for helping me with this undertaking*, even going so far as to pull the buttstock off one of his Marlins and verifying the triggers spacer orientation while on the phone with me. Also, my thanks to the other 16 ga. Forum members who had previously posted about their own techniques to disassemble / troubleshoot one of these shotguns. I could not / would not have even thought to undertake this project without their previous postings to use as a guide. I am not an “expert” or a gunsmith or even particularly handy, thus I have written this guide for someone similarly challenged on my skill level; I’m sure most Forum Members will find some of my instructions more than a little elementary, so I offer my apologies in advance.
* whenever you see * in this article, it indicates info straight from Nick to me.

The equipment and supplies you probably will need:
a) 10” long shanked flat blade screw driver , or T bar screw driver socket with extensions.
b) a vise to hold the receiver, you will need pad it.
c) Combinations of : #0004 steel wool, 200 & 400 grades of emery cloth( wet / dry sand paper) , fine files, Arkansas stone, and / or polishing paste.
d) small Ziploc bags to put various parts into
e) a box ( no bigger than shoe box is warranted) to put parts into.
f) Aerosol gun scrubber or automotive brake cleaner to clean parts
h) an old aluminum bread or pie pan.
I) soft cotton rags, Q-tips.
j) a dremel style tool with a felt buffing head.
k) a chopstick or other strong , small diameter wooden dowel about 8” long.
l) your favorite gun oil (mine is Ballistrol – like my good friend Hickok 45 uses)
m) punch rod or drill bits in the right size.
DISASSEMBLY STEPS:
1. COCK THE SHOTGUN ! (Just move the top lever to the right and open the action as if you were going to put a couple of shells in it). This engages the sears, which is necessary to facilitate removing the striker box without having a special machinist’s vise. Close the barrels and make sure the safety has engaged – this is an automatic safety gun in its original condition.
2. Remove the forend. If your gun is the older model with just 2 screws showing on the bottom of the forend, just stabilize the buttstock on the floor and pull the forend downward and away from the barrels; it is simply held on by a steel spring. If your forend has the later latch mechanism, just pull up on the latch and remove the forend.
3. Secure the receiver in your padded vise, making sure the butt stock is not held by the vise. I didn’t have any wood suitable for using as a pad on my vise jaws, so I simply cut 2 strips of leather from an old military style sling and secured them to the vise jaws using masking tape made into a loop – one side on the leather and other side against the vise jaws. This worked fine for me. You may need to improvise here, but the important thing is to keep the jaws from marring the receiver while still maintaining a good grip on the receiver.
[URL=http://www.jpgbox.com/page/56740_600x400/] [/URL]
[URL=http://www.jpgbox.com/page/56739_600x400/] [/URL]

4. Remove the buttstock by inserting your long screwdriver into the hole in bottom of the buttstock, seating it in the slot on the retaining bolt and simply unscrewing the bolt. Take note of the number of washers on the bolt.
[URL=http://www.jpgbox.com/page/56742_600x400/] [/URL]

The washer closest to the bolt head should be a lock washer and there could be only 1 or 2 washers in front of it or there may be as many as 3 or 4, which was the case on mine. Put the bolt and washers into a plastic baggie, ziplock the bag shut and put in into the parts box. You will probably decide to clean the bolt and its threads and lightly oil the threads before reassembly. When reinstalling this bolt be sure to have the very same number of washers on it.
5. Remove the buttstock by pulling it straight away from the receiver. You may need to give it a very slight rearward tap with a rubber mallet head, but mine slid right off.
6. Orientation. Now that the buttstock is off, this is a good time to get an idea of how the mechanism works. Viewing the receiver from the left hand side notice the “Lazy Z” strip of then metal across the sheet metal sear box. This is the automatic safety reset. If your gun does not have this, then someone previously removed it, making your shotgun a non-automatic safety gun. Notice the two springs in front of the searbox are fully compressed, indicating that the strikers are cocked. Notice at the rear of the searbox how the strikers are mated with the sears. Operate the safety a couple of times and notice its components, how it blocks the rear of the triggers when ON and the movement of the pin on the underside of safety button going over a small “bump “in the thin metal spring. DO NOT RELEASE THE TRIGGERS, as the strikers need to be cocked to enable you to remove the searbox.
[URL=http://www.jpgbox.com/page/56743_600x400/] [/URL


7. Before proceeding with further disassembly, I removed the receiver from the vise and sprayed it down out in the garage with the aerosol brake cleaner I had, collecting the drippings into an old aluminum bread pan. I recommend using latex (or better) gloves and wearing eye protectors when doing this. I held the receiver in such a fashion that all the spraying and drippings went away from the finished metal on the outside of the receiver, immediately wiping the finished metal off from any of the nasty stuff. Then put the receiver back into your vise.

8. Remove the safety components by unscrewing the horizontal screw on the left side below the receiver and remove the thin spring (using your needle nose pliers if necessary). Then remove the “lazy Z” automatic safety bar. Then drive the rear safety pin out from left to right using either a punch or a drill bit in the appropriate size and slide the safety part off the guide attached to the safety button on the receiver. Put all these parts in a plastic baggie, ziplock it and put it into your parts box.

9. Drop the rear part of the triggers by driving out the rear pin (in the “hump” in the frame) from left to right. If you’re going to be working on / polishing the triggers themselves, you might as well drive out the forward pin also at this time and drop the two triggers and their spacer. Remove the triggers, spacer and put them and the pins into a plastic baggie, ziplock it and put it into your parts box.

10. Now you’re ready to remove the sear box. First remove the screw on top of the receiver just in front of the safety button.
[URL=http://www.jpgbox.com/page/56508_600x400/] [/URL]

Then remove the sear box with the strikers and springs attached as one unit by GENTLY pushing on the searbox from left to right. (the early, early, early versions of this gun had the searbox removed from the left side – and that is an entirely different animal – and a real beast I’m told *…I have no help to offer removing it). Push near the bottom of the searbox and take your time, when its about half way out I found I had to use a little more muscle and then it came out with me sort of twisting the bottom up/out and towards the front of the receiver. Hard to explain; you may have to play with it awhile, but eventually it will come out.

11.Remove the strikers and springs from the searbox. Place the searbox in the vice with the firing pin end pointing down with a block of wood about 1 ½” underneath the pins. Release the stikers one at a time by pushing on the rounded knob protruding out the bottom the searbox with your chop stick.
[URL=http://www.jpgbox.com/page/56510_600x400/] [/URL]

When this is done, remove the searbox from the vice and carefully remove the strikers, springs and square washers one striker at a time. Be sure and mark these carefully as they need to be reassembled in the exact same orientation; do not mix the springs and washers between the two strikers, put them in separate baggies and keep them separate. Also note that the hole in the top square washer is not centered – purposefully. The bottom one may not either. These need to be put back on the strikers in the exact same orientation, so figure out a way to tag them so you can reassemble them correctly.

12. Remove the springs on the rear side of the sears so you can later polish the sear flats. You need secure the searbox in you vise and then take hold of one of the legs of the spring entering into the searbox with your needle nose pliers and pull it out.
[URL=http://www.jpgbox.com/page/56511_600x400/] [/URL]


Repeat on the other side and then lift the spring away from the searbox. Do the same with the other spring. Again, keep these springs separate from each other, as they need to go back exactly as they came out* i.e. the spring you take out of the top, needs to go back in the top. Mark them so you can reassemble them correctly and put them into a plastic baggie and into your parts box.
THERE IS NO NEED TO FURTHER DISASSEMBLE THE SEARBOX.
All other functions on my gun were working properly, so I did not undertake further disassembly.
Cleaning and Polishing: Take the receiver out to the garage and spray it off with your aerosol cleaner again, now that all the guts of the action have been removed. Then wash all the various parts individually in the cleaner stuff. Inspect each part. Any rough areas smooth up with your stone, emery cloth, polish or fine files. Be sure to smooth out even the holes in the square striker washers*. DO NOT MESS WITH THE SEAR EDGES THEMSELVES OR YOU WILL RUIN YOUR GUN*. You can use polish on the strikers and sear flats though, and you should*. My one striker was showing signs of rubbing against the top of the frame and part of the safety components. Nick also said to “break the corners” on all areas of the frame and the searbox which interface with each other*. By this he means take your stone or fine file to all corners and edges of the searbox and the right side of the frame area where the searbox gets inserted. Use a needle file to break the corners on the holes where the pin portion goes through the frame.* I basically put the very fine files, 400 grit paper, 0000 steel wool or the polish to everything.
Fixing my difficult safety. I was able to identify the cause of my difficult safety issue: the little “bump” in the safety spring was too severe and thus the culprit. I fixed this by putting the spring on the anvil part of my vise and lightly tapping down on the bump with a small hammer; testing my results, making another few taps, testing again, etc. until I got it just right.
Lightening my trigger pull. I was half hoping to find some hitch or burr in the trigger mechanism that I could clean up, but nothing was amiss. As it turned out, the triggers were improved somewhat, but still heavy after all my efforts.
REASSEMBLY STEPS:
1. If you have dropped both triggers, start the reassembly with installing the triggers, making sure you have the proper orientation for the spacer between the triggers.
[URL=http://www.jpgbox.com/page/56513_600x400/] [/URL]


Start with the rear trigger pin holes and get the rear pin put in first; this makes the front trigger holes and pin somewhat easier to lineup. Put the front pin in securing all three components. It’s then necessary to drive out the rear pin again and drop the rear portion of the triggers so the searbox can be refitted.
2. Reinstall the two coil springs on the rear side of the sears. To do this, first secure the searbox in your vice. Start the two legs of the spring into the appropriate holes, then put the chopstick through the coil part of the springs and push the chop stick straight down until the horizontal section of the spring snaps into place.
[URL=http://www.jpgbox.com/page/56512_600x400/] [/URL]


3. Now you’re ready to assemble the sear box. Make sure your orientation of the strikers and components is correct.

[URL=http://www.jpgbox.com/page/56515_600x400/] [/URL]

Note the two strikers have different tail sections, they are not interchangeable; top is always top, bottom is bottom.

4. Put your searbox in the padded vise with the front end facing up and insert the two strikers into their appropriate openings. Press down on one striker at a time until it engages with the sear.
[URL=http://www.jpgbox.com/page/56516_600x400/] [/URL]


Then press down the other striker until it engages. Your searbox should now look like this.

[URL=http://www.jpgbox.com/page/56514_600x400/] [/URL

5. If you removed the safety component attached to the rear part of the frame via a pin, reinsert it now and drive the pin back in.
6. Reinsert the sear box. This is a little tricky, so be patient! Insert the searbox from the right side of the frame by first introducing / aligning the front firing pin portion of the strikers at their respective holes in the back of the frame. You will need to have the searbox at a slight angle ( maybe 10 degrees give or take) to do this. Next turn the searbox down and inward into the frame opening. You may have the coil part of the sear springs hang up on the hump in the frame, just take your chopstick or whatever is handy and gently push the coil up on the top of the frame hump and continue pushing the searbox to the left until it is fully seated in place.* Once the searbox is fully in place, reinstall the top screw through the frame in front of the safety.
7. Reinstall the safety, first putting the Lazy Z bar back in place; then install the straight spring and then the screw that holds it all in place.
8. Put the buttstock backon . I made sure my bolt was protruding through the stock and held it there with my socket screwdriver while I slid the buttstock back onto the receiver. Tighten the bolt making sure that you haven’t cross-threaded the screw. You will know when its tight enough from the feel of the lock washer.
9. Take the receiver out of the vise, attach the barrels and then the forend. Open the action and insert a couple of snap caps. Operate both triggers to make sure everything is working properly. Repeat a couple of times…. YOUR DONE !!!
Back to top
View user's profile Send private message
PRONGHORNSOUTH
PostPosted: Thu Apr 11, 2019 8:48 am  Reply with quote



Joined: 30 Dec 2012
Posts: 269
Location: Chocolate City, Florida

Super nice job!
Great work!
Very Happy
Back to top
View user's profile Send private message
doc walden
PostPosted: Sun May 05, 2019 4:21 pm  Reply with quote
Member
Member


Joined: 13 Jul 2004
Posts: 20
Location: Rising Sun, Maryland

This was a great posting. I haven’t read such a comprehensive write up previously..thank you so very much. Very Happy Laughing

_________________
"Not all who wander are lost" J.R.R. Tolkien
Back to top
View user's profile Send private message Send e-mail
rdja
PostPosted: Tue May 07, 2019 12:47 pm  Reply with quote
Member
Member


Joined: 02 Sep 2010
Posts: 829
Location: SW Ohio

This needs to be a "sticky" and stay at the top of the forum.
Back to top
View user's profile Send private message
spittinfire7
PostPosted: Thu May 16, 2019 3:12 pm  Reply with quote



Joined: 17 Sep 2008
Posts: 32
Location: Maiden, NC

This is outstanding. Thank you.
Back to top
View user's profile Send private message
thunderstick
PostPosted: Sun Sep 01, 2019 12:06 pm  Reply with quote



Joined: 23 Jun 2005
Posts: 185
Location: Boulder,Colorado

Thank you, Gentlemen. I'm still wanting to find a smith to work on the triggers to lighten them up. After next week's dove hunt, I may take it to a local guy and see if he can help with those heavy triggers.
Back to top
View user's profile Send private message
rdja
PostPosted: Wed Sep 04, 2019 11:38 am  Reply with quote
Member
Member


Joined: 02 Sep 2010
Posts: 829
Location: SW Ohio

thunderstick wrote:
Thank you, Gentlemen. I'm still wanting to find a smith to work on the triggers to lighten them up. After next week's dove hunt, I may take it to a local guy and see if he can help with those heavy triggers.


Take the springs back out and take it to a hardware store and see if you can match it up with a similar spring of a lighter type. I had someone work on the triggers as it was not hitting the primers hard enough. They put in very heavy springs and the triggers were way too heavy. I got springs from Numrich gun parts that were listed for the gun. They were just a lighter spring and now the triggers are much better..
Good luck.
Back to top
View user's profile Send private message
thunderstick
PostPosted: Tue Sep 17, 2019 4:18 pm  Reply with quote



Joined: 23 Jun 2005
Posts: 185
Location: Boulder,Colorado

Thanks for the suggestion ! I will endeavor to try that. Shouldn't be too hard to find some springs ? Am I looking for the same length, just lighter compression ?
Back to top
View user's profile Send private message
rdja
PostPosted: Fri Sep 20, 2019 11:11 am  Reply with quote
Member
Member


Joined: 02 Sep 2010
Posts: 829
Location: SW Ohio

thunderstick wrote:
Thanks for the suggestion ! I will endeavor to try that. Shouldn't be too hard to find some springs ? Am I looking for the same length, just lighter compression ?


That is where I would start.
A longer spring with similar compression would work too, then clip off small parts of the end, about half a turn at a time. Lots of work though, cutting and trying, then taking them out again, etc, etc.
Back to top
View user's profile Send private message
Display posts from previous:   
All times are GMT - 7 Hours

View next topic
View previous topic
Page 1 of 1
16ga.com Forum Index  ~  16ga. Guns

Post new topic   Reply to topic


 
Jump to:  

You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum




Powered by phpBB and NoseBleed v1.09