The adjustment for throw-out can be controlled by taking up the friction grip adjustment, the latter being identical with the take up adjustment just described, as these too are taken care of by the same mechanical means to make the adjustment on the clutch.
Disc Clutch Cleaning; Dry Plate.—Dry plate clutches do not require any oil, except that the grease cups (which provide lubrication for the sleeve shaft and bearings) be filled weekly and given a half turn every second day. The housing and plates should be cleaned whenever slipping becomes noticeable. To do this remove the cover from the housing, and the drain plug from the bottom, hold the clutch out, and squirt kerosene over the plates with a dope gun. This will remove the grease from the plates, and also any dirt or grit that may have lodged in the bottom of the housing.
Disc Clutch Cleaning; Wet Plate.—The wet plate clutch is cleaned in the same manner as the dry plate, except that the plug is first removed from the bottom of the housing and the oil drained off before using the kerosene. After the plates and housing have been cleaned, replace the drain plug and fill the housing up to the clutch shaft with a heavy cylinder oil.
CONE CLUTCH CLEANING
Cone clutches are always in perfect condition when leaving the factory and should not require any further attention during the first season or for eight to ten thousand miles of service.
After that it is usually necessary to replace the leather, or reline the cone, which makes it as good and as serviceable as when it was new.
New Clutch Leathers.—New clutch leathers may be obtained from the manufacturer, or from the service station, by giving the number and model of the car. New clutch leathers obtained in this way are cut, shaped, and have the ends cemented, and are ready to be slipped on or off, over the cone and riveted into place. However, the leather must first be soaked in water or Neat’s foot oil to make it soft and pliable. This allows it to be driven or stretched over the cone. The rivets must be counter-sunk to prevent the heads from extending above the top surface of the leather, which would cause the clutch to “grab” or jerk upon being engaged.
Fig. 108. Cone Clutch Leathers—Pattern—Cutting
Measuring and Cutting Clutch Leathers.—Whenever possible it is advisable to purchase clutch leathers cut and cemented, ready to put on. But in case of emergency or when the proper size cannot be obtained, a new leather may be cut from a piece of leather three-sixteenth of an inch in thickness using the old leather as a pattern. But in case the old leather is not available to serve as a pattern, proceed in the following manner which is illustrated in [Fig. 108], which shows how to make an exact pattern out of paper without going into technicalities. Take a piece of heavy wrapping paper, forty or fifty inches long and twenty inches wide, lay the cone on the left hand edge about one inch from the bottom of the sheet, roll the cone keeping the paper flat on the face until the starting edge meets the sheet, hold the wrapped cone and draw a line around the inside of the paper, letting the pencil rest against the edge of the large diameter of the cone; repeat at the small end of the cone, then draw a line parallel to the starting edge where it meets the sheet. This will give you a pattern similar to that shown with the dotted lines in [Fig. 108].