See Fig. 1. First set the Change-0-Matic feed in the .003 position as shown at "A". This will enable the rotary change gear bracket inside gear case "C" to clear the frame of the milling machine when removing gear case.
Next remove the four cap screws marked "B'. Gear case "C" can then be removed by pulling directly away from inner gear plate "D".
FIGURE 2
See Fig. 2. Remove cap screw "E" and pull off the feed gear.
With a thin end wrench unscrew stud "F", the complete tumbler gear assembly may then be removed from the machine.
Next remove four cap screws "G", inner gear plate "D" may then be pried off with the aid of a screw driver. Care should be taken not to damage or lose the two dowel pins "H". This may be accomplished by prying alternately on opposite sides of the plate.
See Fig. 3. Loosen set screw "B" and unscrew collar "C" by turning counter-clockwise. Care should be exercised not to lose the small cushion of soft material that is located under set screw "B". Gear "G" may now be removed by pulling directly away from the head.
Next pry out Woodruff key "E" and pull collar "H" off from the spindle. Remove set screw in collar "D" and two set screws "F" in gear "I".
With a lead hammer or a machinists hammer and a block of wood, carefully drive the spindle "A" in the direction shown by the arrow until Woodruff key "J" appears beyond the face of gear "I".
The spindle then should be rotated until the Woodruff key enters the notch in the top of dust cover "M". After the key has entered the notch, proceed to drive out the spindle the rest of the way; dust cover "N" will be automatically removed with it. Care should be exercised not to lose the various loose parts such as the spindle pulley, spindle gear and adjustment collar when removing the spindle.
FIGURE 3
Next, it is necessary to remove the back gears. Drive out pin "K" in the eccentric handle and removing the two set screws "L". Back gear shaft "0" can be pushed out in the direction indicated by the arrow.
The old belt can now be pulled out of the machine and a new belt inserted.
All parts should be cleaned and oiled before reassembly. By following figure 3 carefully, the various parts may be put back in their proper places.
First, put the back gear assembly together.
Next, assemble the spindle with it's various parts. Proper adjustment for the correct pre-load is accomplished by adjusting collar "C" so there is a noticeable drag on the spindle "A" when turning it over by hand.
All gears should be greased with a gear lubricant equivalent to Keystone #122 gear lubricant.