I don't see any reason that RFC members should be sent off to another site for assembly instructions involving the Ruger Mark II pistol. I'm very surprised that this hasn't been done here previously. I'll start with a completely vacant Ruger Mark II grip frame and go through the step by step procedure that has given me a very good means to get this sometimes daunting job done. This thread will be closed until I can get things organized properly, or so at least even the "newest" RFC member can follow the instructions to a fulfilling outcome.
At this point, disassembly will not be covered, as that's pretty easy to do and there's really no regimented procedure involved, other than a simple caution to not force anything out of place on these pistols. In all circumstances, pins come out very easily.
Here's a picture of all the parts you should have saved after complete disassembly. Look this array of parts over to make sure you have them all, in front of you and available, before you start. In the event you are replacing a factory part with an aftermarket part, I'll try my best to describe how best that works for me.
I use a vise with hardwood false jaws (white ash) to hold the grip frame in a secure position, where the grip frame will stay in place, yet provide access, and expose all the hole locations for the internal parts we're going to install here. I'll provide an equipment list, with pictures at the end of this adventure.
If you want to completely clean every nook & cranny in this pistol, you may want to remove the trigger pin retaining spring. Here's how to get that part back in place.
The hook end of the spring (black arrow) goes behind the pin (white arrow) so that the front end of the spring points toward the front end of the grip frame. The front end of the trigger retaining spring then gets tucked into the right side of the grip frame lug for the receiver.
Now, you can insert the trigger pivot pin into the right side of the grip frame, but only go in as far as the picture shows. This will give us plenty of room to get the trigger into the cut-out for it in the grip frame.
I find it best to install the pivot pin on the disco into the pivot hole in the top of the trigger at this time. This will provide a sort-of-handle to get the trigger into position in the grip frame. If you're using the Ruger factory trigger, or either of the Volquartsen aftermarket triggers, the disco most always pivots very freely in the disco pin hole. the Clark trigger can sometimes provide a very tight fit where the shoulder of that pin fits into the Clark trigger. If you find that condition, you may need to open up the diameter in the Clark trigger with a drill bit one size larger than the shoulder on the pivot pin. Normally, the Volquartsen triggers fit into the cut-out in the grip frame with no problem. The Clark Steel trigger may sometimes need to have the sides of the trigger pushed across a sheet of #220-grit emery paper to reduce the width size and get a proper fit.
Install the trigger while it's attached to the disco, and align the trigger pin to the hole in the trigger. Push the trigger pin to the left, but not all the way through the trigger body. We need to leave room for the bolt stop assembly plunger and spring.
The next parts that go into the grip frame involve the bolt stop assembly plunger and plunger spring. These parts are small and my preference is to use a bent nose tweezers to get the spring and plunger in place, and then oriented just like the picture portrays.
Now we can install the bolt stop assembly. Make sure the rear end of the bolt stop assembly is positioned so the button on the rear end protrudes out of the cut-out for it in the grip frame. When pushing the bolt stop assembly forward, you need to overcome the bolt stop assembly plunger spring by pushing the bolt stop assembly forward with your right hand thumb and attain alignment of the front end of the bolt stop assembly with the hole in the frame. Once you achieve the alignment, the trigger pivot pin can be pushed all the way to the left and, until the left end of the trigger pin is flush with the left side of the grip frame.
The trigger pivot pin needs to look like this and be against the left face of the grip frame. The groove in the right end of the trigger pivot pin should accept the trigger pin retaining spring by snapping into the groove. That's very necessary to keep the trigger pivot pin from drifting out of place to the right.
We can now move to the back of the grip frame and begin installing the parts involved with the sear and hammer operation. First, install the sear pin so that it protrudes 1/8 to 3/16 inch into the inside of the grip frame. I'll then use the bent nose tweezers to position the sear spring onto the end of the sear pin that is now sticking into the grip frame. Pay close attention as to how the sear spring is oriented. The short tail is up, and in back of the springs coils. The longer leg of the sear spring is tucked between the front of the pin below the sear spring pin, and the inside of the frame. Study the picture below.
Once you have the sear spring positioned correctly, use the bent nose tweezers to position the sear in place while you push the sear pivot pin to the right, and through the hole in the sear. Make sure that the sear and sear spring is positioned just like the photo below, for now. Obviously, if you are replacing the factory sear with a Volquartsen sear, this would be the time to do that.
The rear area of the grip frame is where most owners have problems, so hopefully these pictures will help clear the path to getting an understanding of how easily these parts can be installed. The first part we want to get positioned is the "bolt stop thumb piece". Hook the front end of the thumb piece around the button head of the bolt stop assembly that sticks out of the left side of the grip frame. Then, install the hammer bushing pin in far enough that it will hold the thumb piece in position, but only so far, that the right end of the hammer bushing pin is flush with the inside face of the grip frame.
The next component we will need to insert is the safety. Here's where a lot of trouble can happen if a couple of issues are not adhered to. The safety detent and spring are prone to fall out of the safety quite easily unless a dab of grease is inserted into the hole for the detent spring and detent in the safety. Push the sear forward with your left forefinger and the install the safety, thumb button first, through the cut-out in the grip frame with the safety in the "fire" position. Let the top of the sear come backward until the notch in the safety can capture the top of the sear. Then, push the safety up, into the "on" position to lock the sear in place. As you can see by the picture provided, it will stay in place without any help.
Then we need to push the hammer pin in a bit further until it fits flush with the right face of the safety plate.
Next, we need to go back up front and install the trigger plunger spring, and plunger, into the trigger.
Now, we can swing the rear end of the disco backward and insert the right side of the hammer bushing, that protrudes out of the right side of the hammer, into the widow in the disco that it is designed to ride in.
Push the hammer down until the hammer notch engages the sear and then push the left end of the hammer bushing pin to the right until it goes through the hammer bushing and into the hammer bushing bore in the right side of the grip frame.
Make sure that the right end of the hammer bushing pin fits flush with the right side of the grip frame.
The next thing you will need to verify, is that the hammer strut is swinging freely and not hung up behind the sear spring pin. If you look into the rear of the grip frame, it will be easy to verify if the bottom end of the hammer strut is free, or not. At this point, it's a simple matter to push the hammer forward so that the hammer strut is clear of any pins.
Here are some of the tools that I use to make the assembly go well for me. You may find that other gadgets help you to just as well get all the internals installed back into these grip frames. If that works for you......GREAT. I hope that these instructions will at least encourage you to stick with RFC and at least try these methods to see if they work for you. If they don't, please feel free to send me PM with your suggestions as to how this process can be made easier.
A third set of hands is always a good idea when working on these Ruger Mark pistols, and makes things more easy to work on and around with the pistol gripped securely in this vise that has hardwood false jaws holding it firmly.
Here are some of the tools that I have found to be handy with reassembly, and that help get parts into some tight areas where fingers don't seem to belong.
#1) This is a tool I made up, long ago, from a small screwdriver that serves two purposes. It pulls the mainspring housing latch down for removal, and the hooked end aids in changing out the extractor, if that's a part of the current plan.
#2) A bent nose tweezers helps with getting parts down into place and will help get that part positioned properly for assembly and then operation.
#3) A 1/8 inch drift punch will help with removing (pushing) pins out of place.
#4) The is a #180-3 driver bit from Brownells. Used to remove grip screws without buggering up the slots.
#5) I prefer to use an engraver "chasing hammer" that has a larger diameter head than the ball peen hammers do. With this hammer I can keep my eyes on the head of a punch, but still hit a punch without missing and putting a ding where it doesn't belong.