Singer 700 series - Page 26

Motor Gear and Clutch Spring:
1. The Clutch Spring, Main Shaft Drive Gear, Hand Wheel and Motor Gear are other areas that I’ve seen worn out.
Primarily due to improper lubrication, or lack of. I’ve seen the metal motor gear destroyed, but yet the fiber main shaft
gear intact without a flaw. You’d think it be the other way around, the metal would out last the fiber part, but not so.
When lubing these parts, I’d recommend a silicon based lube, or genuine motor gear lube, but I found that the silicon, or
even Teflon products work best. A very light coat of grease lube is required, don’t get crazy with it. If you over do it, all
it does is make a mess of the surrounding area, trap dirt and eventually destroy the motor gear. Under no circumstance
use a graphite type lube in this area, or on any other gear or part. Graphite lubes are great, but may cause this area to
wear more rapidly.
2. Remove the Hand Wheel Screw as shown in picture (1).
3. Slide the Hand Wheel and Clutch Spring off the Main Shaft, picture (1), by pulling it to the right of the machine. If the
Clutch Spring doesn’t come off with the Hand Wheel, no big deal. Flat spot
4. Notice once you have the Hand Wheel off, there is a flat spot on the Main Shaft, reference picture (2). When you put
this unit together, the Hand Wheel Screw must seat on this flat spot. Also note that some Hand Wheel Screws may have
a black rectangular spring that goes between the screw and the Hand Wheel. Not all models had this spring, but if yours
does, put it back on as it came off.
5. Check the Clutch Spring and ensure it isn’t broken, picture (3), both tabs should be intact, and the spring should not be
broken. If it is you’ll need part number 172299-003. This spring was used in all 600, 700 series machines, and in the
401, 403, 404, 500, 503 models. So finding one shouldn’t be too much of a problem. Again, your local repair shop may
have one from a torn down machine.
6. Pay attention to the Main Shaft Gear also, it has a beveled area on one side. This bevel must go back on against the
Hand Wheel. This collar is also used to adjust the amount of free play the gear has. A gear to tight will not allow the
clutch spring to work properly, and one to loose will cause motor and gear chatter. Picture (4).
Remove this screw, by turning CCW.
Remove the Hand Wheel by pulling
in this direction.
1
2
N
ote the flat spot on the Main Shaft,
the screw must seat here when
installin
g
the unit to
g
ether.
3
N
ote the bevel on one side of the Main Shaft Gear, it has to fit against the
Hand Wheel, this allows some clearance for the clutch spring to spin
inside the fitted area.
4
Main Shaft Gear part
number - 172312
7/6/2007
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