Moving your machine
Before you decide to move your machine, read this! When I say 'Moving your machine', I don't mean moving it across the room, but if you move it across town, or across country, read on. Seeburg vertical play mechanisms do not like to be in any orientation other than upright; the position they occupy in your machine. In other words, if you lay your machine down on its back without doing anything to the mechanism, there is a very good chance it won't work anymore when it gets to its destination.
The first thing you should do is to obtain the Installation and Operation (I & O) manual for your machine. It's available from www.alwaysjukin.com or www.victoryglass.com (among others) in the U.S. If you're in Europe, try www.jukebox-world.de/index_en.html. Read the I & O manual section titled 'Unblocking', and follow the instructions in reverse order. Make sure you remove all records. Most machines were shipped from the factory with a pair of 4-½ inch thumb-screw bolts to secure the mechanism carriage in place. I believe these are ¼-20 bolts, i.e., ¼-inch in diameter, with 20 threads-per-inch. These bolts will insert through the board the mechanism mounts on or speaker enclosure (accessible through the coin box in most of the newer machines), through the base casting, and into threaded holes in the bottom of the carriage casting. The original bolts were most likely thrown away when the machine was first unpacked. Your I & O manual should tell you where the correct position for bolting the carriage position is, or you can look under the base casting to find them. Move the carriage to this position, and screw the bolts in. Before tightening them, place some soft wood shims or doubled-up corrugated cardboard between the base casting and the mechanism mounting channels. Then hand-tighten the three or four nuts (depending on machine) which mount the base casting to the mechanism mounting channels. Next, hand-tighten the carriage bolts. Now it should be safe to lay your machine on its back for shipping. If the carriage is not secured to the base casting, it will bounce around, most likely damaging the contact block and its wiring. It's also possible that the transfer arm casting or reversing switch will be damaged. If you are shipping the machine in a crate, make sure you put 'This End Up' labels in the correct orientation, and add Fragile labels. Hopefully, the shipper will notice these and not drop it or ship it upside down. Once your machine gets to its new home, make sure you remove the carriage bolts and loosen the base casting nuts before plugging the machine into the wall!
If you can't shim the base casting and bolt the carriage to the mechanism mounting board or speaker enclosure as discussed above, then you should definitely remove the mechanism from the machine. This is also true of the STD3 and later 160-selection machines, where the mechanism is suspended from a metal frame within the cabinet, and all of the home stereos. Again, the I & O manual will tell you how to do this. Before removing the mechanism, remove all records. Make a selection near one end of the magazine, so that the pickup arm moves to the side farthest from the trip solenoid when going into play. Once in play, reject the record and unplug the machine. Manually turn the rubber motor coupling (DO NOT turn the turntable) until you can see the transfer arm moving down into the magazine. Now you can unplug all mechanism cables. Early machines use round cable connectors that have a keyed center prong to insure that they cannot be incorrectly mated with the socket. Sometimes, the center prong breaks, so be very careful to observe which way the connectors plug in. If the center prong is broken, marking the connector and socket will help when you go to plug the connector back in. Some of the newer machines use larger nylon connectors, others use smaller connectors. The larger ones were usually made by AMP (now Tyco, Inc). These connectors have a box at each end into which a prong on the mating connector fits to keep the connector mated. They can sometimes be difficult to disengage. If you simultaneously press both prongs in toward the connector housing, they should unlatch. The mechanism is normally held in the mounting channels by a pair of pins, with a 'nail head' at one end, and a taper at the other. If you push the tapered end toward the channel, the pin should move enough for you to grab the other end and pull it out of the channel. You may need pliers for this. But be careful! The mechanism is fairly heavy (especially the 200-selection and home units) and the weight will be off-center if you prepare it as described above. Now that the mechanism is out of the machine, set it down on an old blanket and hand-tighten the three or four nuts which mount the base casting to the mounting channels. Be sure to keep the mechanism upright! Use the rest of the blanket to shield the record magazine and pickup arm. It's probably a good idea to remove the pickup, so the styluses will not be damaged. Be careful here, too. Sometimes the pickup connections get brittle with age. Do not rest the mechanism on the cable bracket under the carriage. It breaks easily.
If you are moving a home stereo unit, I would definitely suggest you remove the mechanism as described above. Note that this mechanism is hung from four springs, and is quite heavy. Removing it will make the cabinet lighter, and prevent the mechanism from being damaged by bouncing around in the cabinet. To remove the mechanism, you'll have to remove the front panel first. For the AP1,2, and HSC1,2,3 machines, the control center has to come out first.