All Mamiya medium format cameras are designed for heavy professional use and will last indefinitely if properly maintained. These cameras have mechanisms like film transport, shutter and diaphragm blades, flash contacts, etc. The interaction of all parts is controlled by gears, levers, springs, rollers and other mechanical components which are subject to wear and tear and require special lubrication from time to time. Ambient conditions like dust, sand, sea air, and moisture can also affect these mechanisms as well as the exposed glass surfaces of your lenses.

If cameras had odometers like cars, it would be easier to specify when to schedule routine maintenance. Mamiya recommended the following service schedule for the working professional photographer:

Camera bodies should be serviced at about 50,000 exposures, or about every 5,000 rolls of film. Film magazines should be serviced at about 20,000 exposures or 2,000 rolls of film. Lenses with leaf shutters should be serviced at about every 10,000 exposures, or about every 1,000 rolls of film. Mamiya 645 lenses without leaf shutters will seldom require service unless the focusing mount begins to feel rough or the diaphragm shows signs of sluggish operation.

It is worth repeating from the instruction books that there are certain routines which should be followed if cameras or lenses are used infrequently. Lack of use is just as detrimental to many camera mechanisms as hard, frequent use. This is particularly true of leaf shutters, which can become sluggish or inoperative if left sitting for prolonged periods. It is a good idea to periodically exercise all mechanical components of your camera if you store it for long periods between uses. The easiest way to do this is to fire the camera a number of times with no film loaded, several times at each shutter speed. This distributes lubricants and keeps the mechanisms operating freely. Mamiya recommends storing all leaf shutter lenses with the shutters uncocked, which relieve tension on the drive springs and will make them last longer and will keep shutter speeds accurate.

Leaf shutter lenses should be particularly protected from extreme heat. This can vaporize some of the lubricant used in the shutter mechanism and allow it to condense on shutter and diaphragm blades, internal lens surfaces, or other unwanted places.

Unless you have training, you should never attempt to take your camera apart or service it yourself, the likely hood is that you will do more harm than good and just increase the expense when you do take it to a qualified technician. If you do take your Mamiya camera in for service, make certain that the repair shop or technician is experienced in service on Mamiya cameras. If in doubt, it is always best to send the camera to the authorized Mamiya agent in your country.