Singer 491D, Service Manual

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REMOVAL:
If it is found necessary to remove the upright arm shaft H2, it should be
removed in the following manner:-
1. Remove oil pump, as instructed on page 11.
2. Follow the instructions in Steps 2 and 3 for removal of hook shaft on page
10 except that, instead of removing hook shaft, merely remove hook shaft
bevel gear T, Fig. 17.
3. Remove arm top cover.
4. Mark the two bevel gears J2, with chalk or crayon on one tooth of one gear
and the corresponding space between the teeth of the other gear so that
these gears may be re-assembled in their original relative positions
without difficulty, if necessary.
5. Loosen set screws K2 in bevel gear at upper end of upright arm shaft. To
loosen set screw K2, remove screw L2 in the rear of the arm and insert
screwdriver through the hole.
6. Make certain bevel gear at lower end of upright arm shaft is fastened
securely. Then while holding upper bevel gears J2 in mesh, draw upright
arm shaft down and out of machine.
REPLACEMENT:
1. Before installing upright arm shaft, make certain it has the bevel gear Z,
Fig. 17 correctly fastened at the lower end of shaft.
2. Insert upright arm shaft up through upper bevel gear, as shown in Fig. 19.
TO REMOVE AND REPLACE THE UPRIGHT ARM SHAFT (See Fig. 19)
J2
L2
K2
H2
Fig. 19