All old-style Hammond organs, based on the tone wheel generator and synchronous motor, require periodic lubrication. We receive a great many queries on this subject, all of which are answered in the following document.

Generator
Two shallow oiling funnels are centrally placed on the generator's upper surface, about 10cm in from each end. They are about 2.5cm in diameter, and made from white plastic or brass. They may be hidden behind bunches of cables, wooden mounting shelves and other objects. If they are not readily visible, use a torch and poke carefully about until you locate them.

An oiling funnel on the B-3 generator.

STOP! STOP! DANGER!
Pull out the electric power plug from the mains supply first! Never, never forget this. There are un-insulated mains-voltage connections to the start motor (this applies to models with 'START' and 'RUN' switches) and numerous other shock-hazard areas. These funnels lead down into a reservoir running the length of the generator, which can just be seen to appear at either end. From this radiates a fine system of cotton threads, or wicks, which slowly conduct the oil to every bearing. These can only be seen from underneath the generator, together with the tone wheels, axels, and toothed drive wheels. If the opportunity ever arises to observe all this, it will be a sight you will never forget.

The complex mechanism inside the tone wheel generator.


Using the correct oil, this automatic lubrication system will provide all the moving parts with an even flow of oil for a year, when a refill will be required. If you forget a refill or two, the generator seems to survive without noticeable ill-effects. Neglect for more than two or three years, however, will cause greatly accelerated wear. L-100 owners, in particular, must be punctual with oiling since this model seems specially prone to generator wear. Even worse is the home made sawn-off L-100, because of (a) all the heat from the 3 amplifiers, and (b) the oiling funnels being covered over by the mounting board for these amplifiers. Some older organs have a curious system of two larger, more conspicuous funnels which lead the oil to the generator funnels and the synchronous motor simultaneously, along slender copper tubes.

Avoid using this kind of central lubrication system.

You are advised to ignore this system by filling oil in the normal way into the generator's two funnels and the motor's reservoir, since the copper tubes tend to become clogged over the years.
If an organ is known to have been under-oiled, administer a double dose and allow it to stand unused for a week, so that the oil has time to seep forward. This treatment is vital if the generator has started squealing, which is common on L-100's. Persistent squealing is only resolved by replacing the generator. If a touring organ is regularly transported on-end, the lubrication scheme should be broken down into much smaller doses, administered correspondingly more often. Otherwise, after a full lubrication, the oil will run out at the lowest end of the generator.

Motor - old style.
The original synchronous motor, which requires a start motor to bring it up to about full speed, is lubricated by means of a small tin plate reservoir, mounted upon it.

Lubricating the synchronous motor.

This contains a wad of cotton felt, around which are wound several cotton wicks leading out through short copper pipes. These conduct the oil down to the motor's bearings and those of the scanner unit, if fitted. The motor is located to the left of the generator, to which it is connected by an axel and flywheel. Its unique shape is sharply rectangular, and the flat cylindrical object attached to its back is the scanner.

Motor - newer, self starting style.
These have a more conventional cylindrical shape, and are invariably painted blue. There are two lubrication funnels of metal, one at either end, each with a sprung dust flap. In an awkward manoeuvre, the flap must be held open as the oil is applied, and spillage seems unavoidable.

Oiling the newer style motor.

If the oil does not flow down into the funnel, try gently unblocking the narrow tube leading down to the motor with a short piece if wire. If the blockage persists, you will just have to wait for each drop to seep down.

DOSAGES

Generator - organs that are only used occasionally, 2 dessert spoons in each funnel. Organs that are frequently used, 4 spoons in each.
Motor, old style - 1.5 to 2 spoons in the tin reservoir.
Motor, new style - 10 drops in each funnel.
[A dessert spoon is a measure understood by all, whereas the c.c. or fluid oz. is almost impossible to visualise.]

OIL TYPE

There is nothing magic or secret about the type of oil required to give your Hammond organ the correct lubrication. If you live in a country lacking organised Hammond service facilities, a thin, high grade machine oil will have to do. If the wrong oil type is used, this is what happens:

  • "too thin" oil will rush from the reservoirs to the bearings, drowning them with oil and then will run dry.
  • "too thick" oil will seep forward too slowly, causing insufficient lubrication.
  • insufficiently refined oil will pollute and clog the wicks, the impurities accumulating in the wicks over the years. Sometimes this is cleared when use of the correct oil is resumed.

The oil you should use, then, must have an exceptionally high degree of refinement, and must have just the right viscosity to produce a capillary oil-flow rate that almost exhausts the reservoirs in one year. Such specialised and tight-tolerance oil is only available in industrial quantities (by the barrel), thus obliging your supplier to decant it into consumer-orientated packages. We provide this service within Germany, charging €7,00 for a 150ml dispenser.

LESLIE UNITS

Several tone wheel models, e.g. L, R and T, as well as many later models have inbuilt 2-speed Leslie tremolo units. These are invariably in dire need of lubrication, sometimes having never received a drop of oil since leaving the factory. In such cases, if the organ has none the less been put to frequent use, the motor axels and bearings will be worn beyond redemption. The task of lubrication is a grade 3 job, and should be passed on to an engineer. If you are forced to do the job yourself, read carefully the description under the section "Care of Leslie Cabinets" noting the following points:

  • Do not use generator oil to lubricate Leslie motors. It is far too thin, and will quickly evaporate due to the considerable heat of the motors. Use modern, high quality car motor oil.
  • Disconnect the organ from the mains electricity supply before carry out this kind of work.
  • Do not attempt to dismantle the fast and slow motors themselves. This is grade 5 work.
  • After re-assembly, the adjustment for slow motor axel pressure must be carried out with the motor unit in the same orientation as in the organ. This is usually with the axels horizontal, but with later Rotor sonic units, the motors hang vertically, as in Leslie cabinets. If you carry this out with the motors replaced in the organ, with mains power connected, use extreme caution!
  • Odd sizes of 'O'-ring and drive belt are sometimes encountered, so if these need replacement, acquire them in advance of commencing work, as well as the special tools required.