I received a Speed Graphic 4 X 5 camera via mail order. I immediately discovered there was a problem with the rangefinder , as there is not much one can do about this except return the camera, I decided to keep it and attempt the repair. The Kalart installation and synchronization instructions were consulted with the following results.
The instruction manual assumes this is a new installation and you have received the rangefinder new in a box with all the goodies. You will have to read and reread all the instructions to get all the instructions in proper sequence for the repair.
There is a screw marked "b" that is located on the front of the rangefinder. This screw is removed during the installation and does no longer exist. (You can find a replacement screw from a model railroad hobby shop. Get a 1 x 72 screw about 1/2" long and screw it all the way in to hold the mechanism in place for infinity adj.)
If you have to reset the arm or the screw has been loosened for some reason or the other this adjustment must be made again to restore the infinity setting. This is the most important adjustment you have to make as all the others depend on it. Use a screw that fits, if you can find one, or maybe you can as I thought of doing is to drill and tap for a 2-56 machine screw I made this adjustment rather crudely by inserting a small shanked screw driver in the hole and forcing the arm inside the body back while tightening the screw on the arm. This forces the spring loaded shaft that has the arm attached to be forced to the rear.
Once this is done check the infinity adjustment and adjust the eccentric mounted on the track to get an exact adjustment. Be sure that you have already checked or set the long and short adjustments on the front and rear of the main body I got lucky and things fell into place. I had previously attempted several times to make the adjustment without doing the above sequence and believe me, it didn't work. It became rather frustrating.
There is also another screw called "last resort infinity" adjustment located below the right angle prism. Make this adjustment only if nothing else succeeds. My rangefinder was completely out of adjustment including this screw I used another rangefinder to check the distance of the prism to the mounting. Again I got lucky.
The above information assumes that you have set or checked the infinity stops on the track and adjusted the vernier scale to infinity before starting work on the rangefinder Follow the factory instructions for the most part to be successful in synchronizing the rangefinder These comments are meant to be helpful in making repairs
I obtained the Kalart Rangefinder, Installation and Synchronization