Category: 431G

The Singer 431G has a “Cloth Plate and Accessories Container with Bed Extension” that can be removed to allow freearm sewing by pressing the button on the Locking Lever.

The Locking Lever assembly consists of several small parts that may require cleaning, servicing or replacement.

This mechanism is difficult to access because it is covered entirely by the large aluminum Feed Bar.

I was able to access the screws that hold the latch assembly loosening several parts to allow the Feed Bar to move away from the machine bed.

These are the steps that I took to expose the latch screws.

• Set the machine on its right (handwheel) side.
• Remove the Bed Cover Plate on the bottom.
• Remove the Tubular Bed Cover screw and pull the cover toward the end to release it.

• Remove the Motor Hold Down Plate.

• Remove the Terminal Plug from the Motor.

• Pull the Motor down and out.
• Loosen the Feed Bar Connecting Block nuts with an 8mm socket and unscrew the Feed Bar Connecting Block screws. Note: When you reinstall them, center the bar so the presser foot is centered in the slots in the needle plate.

• You do not need to remove the Feed Dogs.
• Do not turn the Feed Bar Aligning Screw.

• Disconnect the Feed Fork from the Feed Rock Shaft by loosening the 8mm nut and pushing out the eccentric screw. Note: The eccentric screw adjusts the height of the feed dogs at their highest point. If it is adjusted too high when you reassemble the machine, you will feel a resistance or a binding when you rotate the handwheel through a full rotation. Adjust it so takes the feed dogs as high as possible without causing the machine to push and bind.

• Remove the set screws holding the Feed Rock Shaft Centers in place.

• Push the centers out to free the Feed Rock Shaft. You can use a small set of diagnonal cutters to help push the centers out. If they do not come out easily, use a heat gun to heat the aluminum around the centers. Once they are heated, they should be easy to push out.

• Once you get the centers out, you should be able to rotate the Feed Rock Shaft to access the Feed Rock Shaft Hinge Pin Set Screw.

• After the set screw is removed, you can pull the shaft out to separate the aluminum Feed Bar from the steel Rock Shaft.

• Remove the steel Feed Bar and set it aside.

• This will allow the aluminum Feed bar to drop appoximately one inch so you can access the latch screws with a right-angle screwdriver.

• This is the view of the latch screws after the bar is dropped.

• Reassemble in reverse order.
• The only adjustment you should need to make is the adjustment of the eccentric screw. Notes are in the teardown section for this portion.

• Assuming the specifications for the 431G and the 401A are the same, adjust this eccentric so the feed dogs protrude above the needle plate by 0.040 – 0.043 inches at their highest point. This is approximately the thickness of a standard paper clip.

I used OCR software to import the parts list for the 431.

I manually compared the 431 parts list with the parts diagram for the 401.

Many of the parts are interchangeable.

ILLUSTRATION REFERENCE NUMBER	PART NUMBER	DESCRIPTION (Qty)	Same as 401A
1	507077	Arm *Spool Pin (2)
2	507078	Spool Pin Damper +3}
3	507079	Spool Pin Washer (2
4	507080	Spool Pin Retaining Ring (2)
5	507076	Stitch Pattern Plate Cover
6	507617	Stitch Pattern Plate
7	507081	Stitch Pattern Plate Cover Complete
8	172259	Tension Bracket Complete
9	172011	Arm Top Cover Thread Guide	YES
10	172234	Arm Top Cover
11	197-852	Tension Bracket Screw	YES
12	172277	Face Plate Catch	YES
13	50258-856	Face Plate Catch and Arm Top Cover Thread Guide Screw (2)
14	170168	Oil Metering Insert (4)	YES
15	172137	Stitch Pattern Plate Cover Spring (left)	YES
16	507075	Stitch Pattern Plate Cover Spring (front)
17	172138	Stitch Pattern Plate Cover Spring (right)	YES
18	1454-819	Stitch Pattern Plate Cover Spring Screw (2)	YES
19	1185-852	Stop Screw
20	59456	Stop Screw Washer
21	172258	Stop
22	50609-852	Thread Guide Post Screw
23	172260	Thread Guide Post (adjustable)
24	140879-803	Spindle and Pulley Stud Lever Hinge Screw
25	226-852	Spindle and Pulley Stud Screw
26	172255	Spindle and Pulley (one Piece) with 15072
27	15072	Bobbin Engaging Pin
28	33730-010	Friction Ring (vinyl)
29	172257	Spindle and Pulley Stud Lever
30	172256	Spindle and Pulley (one Piece)
31	172254	Actuating Slide Spring
32	172252	Actuating Slide with 172254
33	959-803	Actuating Slide Hinge Screw	YES
34	172235-002	Arm Top Cover complete
35	172236-002	Arm Top Cover with Stitch Pattern Plate Cover complete
36	8879	Arm Spool Pin Washer (felt)(2)	YES
37	140996-852	Arm Top Cover Screw (2)	YES
38	172079	Pressure Regulating Thumb Screw Extension Pin Seat	YES
39	170065	Presser Bar Guide Bracket with 453-830	YES
40	453-830	Presser Bar Guide Bracket Set Screw	YES
41	172070	4l 172070 Presser Bar Lifter	YES
42	85-805	Presser Bar Lifter Hinge Screw	YES
43	170067	Presser Bar Spring	YES
44	172068	Presser Bar (hollow)	YES
45	172069	Presser Bar Bushing	YES
46	453-830	Presser Bar Bushing Set Screw	YES
47	172075-001	Presser Foot (hinged) complete (slotted needle hole) for Zig-zag Sewing NOTE: 172075-001 is regularly furnished with this machine	YES
48	140240-852	Presser Foot Thumb Screw	YES
49	507067	Throat Plate Catch Pin pe
50	853-830	Throat Plate Catch Pin (left) Set Screw
51	507068	Throat Plate Catch Pin oy
52	500225-830	Throat Plate Catch Pin (right) Set Screw
53	503583	Throat Plate (slotted for Zig-zag Sewing)
54	507069	Throat Plate Support and Bed Slide Retainer
55	500241-853	Bed Slide Stop Screw
56	503584	Bed Slide
57	503594	Bed Slide Complete
58	500219-832	Bed Slide Spring Screw
59	507015	Bed Slide Spring
60	140752-852	Pressure Regulating Thumb Screw	YES
61	1489-819	Needle Bar Vibrating Bracket Hinge Pin(eccentric) Clamping Screw	YES
62	172061	Needle Bar Vibrating Bracket Hinge Pin (eccentric)	YES
63	172078	Pressure Regulating Thumb Screw Extension Pin	YES
64	172033	Needle Bar (hollow)	YES
65	172037	Needle Bar Ball Bushing (lower) Socket (upper)	YES
66	172231	Needle Bar Vibrating Bracket Hinge Pin Collar with 209-830
67	209-830	Needle Bar Vibrating Bracket Hinge Pin Collar Set Screw	YES
68	172034	Needle Bar Ball Bushing (lower)	YES
69	172036	Needle Bar Ball Bushing (lower) Socket (lower)	YES
70	172220-819	Needle Bar Ball Bushing (lower) Adjusting Screw	YES
71	172144	Thread Guide (lower)	YES
72	172225	Needle Clamp Thread Guide	YES
73	172066	Needle Stop Screw Thread Protector	YES
74	189-821	Needle Clamp Thread Guide and Needle Stop Screw	YES
75	140751-853	Needle Thumb Screw	YES
76	172223	Needle Clamp Body	YES
77	172224	Needle Clamp 172223 with 140751-853	YES
78	50311-830	Needle Bar fall Rushing (lower) Adjusting Screw Set Screw	YES
79	172058	Needle Bar Vibrating Bracket	YES
80	998-830	Needle Bar Driving Arm Hinge Bracket Hinge Pin Set Screw	YES
81	50311-830	Needle Bar Ball Bushing (upper) Adjusting Screw Set Screw	YES
82	1115-803	Needle Bar Driving Arm Hinge Bracket Screw (2)	YES
83	172220-819	Needle Bar Ball Bushing (upper) Adjusting Screw	YES
84	172036	Needle Bar Ball Bushing (upper) Socket	YES
85	172034	Needle Bar Ball Bushing (upper)	YES
86	172050	Needle Bar Driving Arm Hinge Bracket	YES
87	172051-001	Needle Bar Driving Arm Hinge Bracket Hinge Pin	YES
88	172060-001	Needle Bar Vibrating Bracket Complete	YES
89	172336	Rotating Hook Robbin (Plastic)	YES
90	503602	Rotating Hook Bobbin Case
91	172202	Rotating Hook Bobbin Case Tension Spring	YES
92	141030-830	Rotating Hook Bobbin Case Tension Spring Screw	YES
93	1172-806	Rotating Hook Bobbin Case Tension Regulating Screw	YES
94	503603	Rotating Hook Bobbin Case Complete
95	507084	Rotating Hook
96	503604	Rotating Hook 507084 with 503603
97	172087-002	Rotating Hook Bobbin Case Cushion Spring Bracket Adjusting Stud (eccentric)	YES
98	507065	Rotating Hook Bobbin Case Position Finger
99	662-833	Rotating Hook Bobbin Case Cushion, Spring Screw (2)	YES
100	172084	Rotating Hook Bobbin Case Cushion Spring	YES
101	172085	Rotating Hook Bobbin Case Cushion Spring Bracket	YES
102	172086	Rotating Hook Robbin Case Cushion Spring Bracket Complete (172084, 172085, two 662-833)	YES
103	172285	Rotating Hook and Position Finger Bracket Spring	YES
104	172096	Rotating Hook Flanged Rushing	YES
105	50311-830	Rotating Hook Bobbin Case Cushion Spring Bracket Adjusting Stud (eccentric) Set Screw	YES
106	507048	Rotating Hook and Position Finger Bracket
107	140702-830	Rotating Hook and Position Finger Bracket Set Screw (2)	YES
107	140702-830	Rotating Hook Bobbin Case Position Finger Set Screw	YES
107	140702-830	30 Rotating Hook Flanged Bushing Set Screw	YES
108	507049	Rotating Hook and Position Finger Bracket Complete
109	507050-002	Rotating Hook and Position Finger Bracket Complete
110	172164	Light Lead Clip	YES
111	507618	Stitch Pattern Indicator Plate
112	500291	Stitch Pattern Indicator Plate Screw (right and left)(2)
113	140754-819	Disc Selector Arm (front) Stop Screw	YES
114	500292	Stitch Pattern Indicator Plate and Light Lead Clip Screw (middle)
115	507569-810	Face Plate Catch Drive Screw
116	507615	Threading Diagram
117	507074	Face Plate
118	170032	Face Plate Catch Hinge Pin (2)
119	172294-002	Face Plate Complete
120	1253-833	Cloth Plate and Accessories Container Cover Spring Screw (2)
121	507022	Cloth Plate and Accessories Container Cover Spring (2)
122	507035	Cloth Plate and Accessories Container Spool Pin (short)
123	507034	Cloth Plate and Accessories Container Spool Pin (long)
124	507020-002	Cloth Plate and Accessories Container Cover
125	5079017-002	Cloth Plate and Accessories Container
126	507021	Cloth Plate and Accessories Container Cover Catch
127	578-819	Cloth Plate and Accessories Container Cover Catch Screw
128	452-830	Cloth Plate and Accessories Container Locking Lever Stud Set Screw
129	507032	Cloth Plate and Accessories Container Position Pin (back)
130	452-830	Cloth Plate and Accessories Container Position Pin (back) Set Screw
131	507031	Cloth Plate and Accessories Container Locking Lever Stud Spring
132	507030	Cloth Plate and Accessories Container Locking Lever Stud
133	507033	Cloth Plate and Accessories Container Position Pin (front)
134	50150-830	Cloth Plate and Accessories Container Position Pin (front) Set Screw
135	???059	Bed Extension stop Pin
136	172203	Cloth Plate and Accessories Container Cushion	YES
137	140809-805	Cloth Plate and Accessories Container Cushion Screw	YES
138	507018-002	Cloth Plate and Accessories Container
139	51108-851	Bed Extension Hinge Screw (back)
140	170130	Bed Extension Hinge Screw (back) Friction Washer (2)
141	170131	Bed Extension Hinge Screw (back) Washer
142	507009-002	Bed Extension
143	140585-352	Bed Extension Hinge Screw (front)
144	507019-002	Cloth Plate and Accessories Container with Bed Extension Complete
145	507005-002	Bed Cover (tubular
146	507007	Bed Cover (tubular) Position Screw Stud
147	140809-805	Bed Cover (tubular) Cushion Screw	YES
148	172203	Bed Cover (tubular) Cushion	YES
149	507006-002	Bed Cover (tubular) 507005-002 with 140809-805, 172203 and 507007
150	158-852	Bed Cover (tubular) Screw
151	507619-001	Lamp Shade
152	172276	Lens (clear glass)	YES
153	170126	Lens Clamp	YES
154	228-805	Lens Clamp Screw	YES
155	174561-002	Lamp Shade Complete
156	500294	Lamp Shade Screw
157	209-830	Disc Selector Arm (front) Stop Collar Set Screw	YES
158	172318	Disc Selector Arm (front) Stop Collar with 209-830
159	209-830	Disc Selector Arm (front) Stop Set Screw	YES
160	172133	Disc Selector Arm (front) Stop with 209-830	YES
161	50123-849	Disc Selector Arm (back) Knob Shaft Stop Screw	YES
162	140857-819	Disc Selector Arm (back) Knob Shaft Bushing Screw	YES
163	172125	Disc Selector Arm (back) Knob Shaft Bushing	YES
164	507620	Disc Selector Arm (back) Knob Shaft
165	941-830	Disc Selector Arm (back) Set Screw	YES
166	959-803	Disc Selector Arm (back) Bracket Hinge Screw	YES
167	172117-001	Disc Selector Arm (back)	YES
168	172119	Disc Selector Arm back Bracket	YES
169	172196-001	Disc Selector Arm (back)	YES
170	219-819	Disc Selector Arm (front) Indicator Screw	YES
171	172132-002	Disc Selector Arm (front) Knob	YES
172	172244	Disc Selector Arm (front) Indicator
173	172245-002	Disc Selector Arm (front) Knob
174	172127	Disc Selector Arm (front)	YES
175	172128	Disc Selector Arm (front) Bracket	YES
176	959-803	Disc Selector Arm (front) Bracket Hinge Screw	YES
177	172197	Disc Selector Arm (front) Complete	YES
178	390-819	Disc Selector Arm (front) Knob Screw (3)	YES
179	172246-002	Disc Selector Arm (front) Knob Complete
180	507060	Cloth Plate and Accessories Container Locking Lever Releasing Button
181	507028	Cloth Plate and Accessories Container Locking Lever Releasing Button Hinge Pin
182	507024	Cloth Plate and Accessories Container Locking Lever
183	507024	Cloth Plate and Accessories Container Locking Lever 597023 with 507028 and 507060
184	500220-803	Cloth Plate and Accessories Container Locking Lever Spring Hinge Screw
185	507029	Cloth Plate and Accessories Container Locking Lever Spring
186	507025	Cloth Plate and Accessories Container Locking Lever Hinge Bracket
187	191-805	Cloth Plate and Accessories Container Locking Lever Hinge Bracket Screw (2)
188	507019-002	Bed Leg (back)
189	507064	Bed Leg (back) Position Pin
190	507011-002	Bed Leg (back) 507010-002 with 507064
191	172203	Bed Leg (back) Cushion	YES
192	140809-805	Bed Leg (back) Cushion Screw	YES
193	507012-002	Bed Leg (back)
194	129-819	Bed Leg (back) Screw
195	50311-830	Needle Bar Driving Arm Ball Pivot Set Screw	YES
196	172053-001	Needle Bar Driving Arm Plate Pin (lower)	YES
197	172054-001	Needle Bar Driving Arm Plate Pin peal 172053-001 with 50311-830	YES
198	172055-001	Needle Bar Driving Arm Plate Pin panel	YES
199	50311-830	Needle Bar Driving Arm Plate Pin (upper Set Screw	YES
200	172046-001	Needle Bar Driving Arm	YES
201	172052-001	Needle Bar Driving Arm Plate	YES
202	172049	Needle Bar Driving Arm Ball Pivot	YES
203	172048-001	Needle Bar Driving Arm Complete	YES
204	172057-001	Needle Bar Driving Arm Plate Tension Arm Spring	YES
205	172333-001	Arm Oil Shield
206	170179	Feed Regulator Hinge Screw Tension Spring	YES
207	172179	Feed Regulator with 1120-830	YES
208	1120-830	Feed Regulator Stud Set Screw	YES
209	172170	Feed Regulator Stud	YES
210	172180	Feed Regulator with 172179 and 172170 (for agents only)
211	500293	Stitch Indicator Plate Screw (2)
212	172172	Feed Regulator Stud Slide Actuating Thumb Nut	YES
213	172173	Feed Regulator Stud Slide Actuating Thumb Nut Washer	YES
214	990-852	Feed Regulator Stud Slide Actuating Thumb Nut Washer Screw	YES
215	140767-803	Feed Regulator Hinge Screw	YES
216	170180	Feed Regulator Hinge Screw Tension Spring Seat	YES
217	507052-002	Stitch Indicator Plate with Machine Class Number and Trade Mark (etched 431G)
218	172171	Feed Regulator Stud Slide	YES
219	172120	Disc Selector Arm (back) Bracket Follower	YES
220	172121	Disc Selector Arm (back) Bracket Follower Index Pin	YES
221	140702-830	Disc Selector Arm (back) Bracket Follower Index Pin Set Screw	YES
222	1429-803	Needle Bar Driving Arm Plate Tension Arm Screw Stud	YES
223	172056	Needle Bar Driving Arm Plate Tension Arm	YES
224	172129	Disc Selector Arm (front) Bracket Follower	YES
225	172130	Disc Selector Arm (front) Bracket Follower Index Pin	YES
226	448-830	Disc Selector arm (front) Bracket Follower Index Pin Set Screw	YES
227	172126	Disc Selector Arm (back) Knob Spring	YES
228	172243	Disc Selector Arm (back) Indicator
229	185-805	Disc Selector Arm (back) Indicator Screw	YES
230	172123-002	Disc Selector Arm (back) Knob	YES
231	140753-819	Disc Selector Arm (back) Knob Screw (2)	YES
232	507621	Disc Selector Arm (back) Knob Cap
233	172307	Spool Thread Pull-off Finger
234	140082-849	Spool Thread Pull-off Finger Set Screw
235	172288	Needle Bar Connecting Link with 140082-849 and 172307
236	172323	Needle Bar Connecting Stud
237	172289	Needle Bar Connecting Link 172288 with 172323
238	1266-830	Needle Bar Clamping Screw	YES
239	172043	Needle Bar Connecting Stud Hinge Pin	YES
240	172044	Needle Bar Connecting Stud Hinge Pin 172043 with 1266-830	YES
241	172145	Thread Take-up Stud	YES
242	45825	Thread Take-up Lever Link	YES
243	45824	Thread Take-up Lever Hinge Stud	YES
244	172330	Thread Take-up Lever
245	172331	Thread Take-up Lever Complete
246	1130-805	Thread Take-up Lever Link Hinge Stud Cap Screw	YES
247	173558	Thread Take-up Lever Link Hinge Stud	YES
248	33704	Thread Take-up Lever Link Hinge Stud 173558 with 1130-805	YES
249	172332	Thread Take-up Lever
250	941-830	Thread Take-up Lever Link Hinge Stud Set Screw	YES
251	500311-850	Chain Stitch Thread Guide Set Screw
252	503619	Chain Stitch Thread Guide
253	140886-830	Needle Bar Crank Position Screw	YES
254	172003	Arm Shaft (horizontal) Bushing (front)	YES
255	1259-830	Thread Take-up Stud Set Screw	YES
256	170006	Arm Shaft (horizontal) Collar with 453-830	YES
257	453-830	Arm Shaft (horizontal) Collar Set Screw	YES
258	172002	Arm Shaft (horizontal) with Needle Bar Crank	YES
259	172302	Arm Shaft (horizontal) Bushing (back)	YES
260	172005	Arm Shaft (horizontal) Counterbalance	YES
261	140559-803	Arm Shaft (horizontal) Counterbalance Set Screw	YES
262	172298	Hand Wheel Gear (Textolite)
263	172303	Hand Wheel Gear (Nylon) NOTE: No. 172303 may be used as alternate to No. 172298
264	170021	Hand Wheel Snap Ring	YES
265	1972299-001	Hand Wheel Gear Spring
266	172297-001	Hand Wheel
267	172300-001	Hand Wheel Complete
268	172317	Clamp Stop Motion Clamp Washer
269	500788-002	Clamp Stop Motion Clamp Nut
270	§0025-851	Clamp Stop Motion Clamp Stop Screw
271	140558-830	Arm Shaft (horizontal) Bevel Gear Feed Cam and Feed Lifting Eccentric Set Screw	YES
272	140992-830	Arm Shaft (upright) Bevel Gear (upper) Set Screw	YES
273	170141	Pair of Gears (upper Shaft) (for Agents use in all territories except USA and Canada) NOTE: No. 170141 is not furnished to USA and Canadian Agencies. The machine must be returned to the factory for gear replacements.
274	170132	Arm Shaft (upright) Bushing (upper)	YES
275	172006	Arm Shaft (upright)	YES
276	45706	Arm Shaft (upright) Bushing (lower)	YES
277	140992-830	Arm Shaft (upright) Bevel Gear (lower) Set Screw	YES
278	140992-830	Rotating Hook Drive Shaft Bevel Gear (back) Set Screw (2)	YES
279	170140	Pair of Gears (lower shaft) Nos. 170121 and 170123 (for Agents use in all territories except U.S.A. and Canada) NOTE: No. 170140 is not furnished to USA and Canadian Agencies. The machine must be returned to the factory for gear replacement.
280	140992-830	Rotating Hook Drive Shaft Bevel Gear (front) Set Screw	YES
281	140992-830	Rotating Hook Bevel Gear Set Screw	YES
282	172210-002	Pair of Gears (lower shaft) 172208-002 and 172209 (for Agents use in all territories except USA and Canada) NOTE: No. 172210-002 is not furnished to USA and Canadian Agencies. The machine must be returned to the factory for gear replacement.
283	140702-830	Rotating Hook Drive Shaft Bushing (front) Set Screw (2)	YES
284	237-830	Rotating Hook Drive Shaft Collar Set Screw
285	140702-830	Rotating Hook Drive Shaft Bushing (back) Set Screw	YES
286	507051	Rotating Hook Drive Shaft Bushing (front)
287	172324	Rotating Hook Drive Shaft Collar with 237-830
288	172093	Rotating Hook Drive Shaft	YES
289	170078	Rotating Hook Drive Shaft Bushing (back)	YES
290	172328	Feed Forked Connection with 141064-805	YES
291	141064-805	Feed Forked Connection Slide Block Screw stud	YES
292	172329	Feed Forked Connection Slide Block	YES
293	507037	Feed Bar Aligning Slide Block
294	507038	Feed Bar Aligning Slide Block Stud (eccentric)
295	140710-830	Feed Bar Aligning Slide Block Stud (eccentric) Set Screw
296	170049-803	Feed Rock Shaft Center (2)
297	140702-830	Feed Rock Shaft Center Set Screw (2)	YES
298	500222-803	Feed Forked Connection Hinge Screw (eccentric)
299	1520-813	Feed Forked Connection Hinge Screw Nut	YES
300	8507045	Feed Rock Shaft
301	507046	Feed Rock Shaft Hinge Pin
302	447	Feed Rock Shaft Hinge Pin Set Screw
303	507036	Feed Bar with 447-830 and 140558-830
304	50128-803	Feed Dog Clamping Screw
305	507043-803	Feed Dog Adjusting Stud (eccentric)
306	507042	Feed Dog
307	140558-830	Feed Dog Adjusting Stud (eccentric) Set Screw	YES
308	500221-803	Feed Bar Connecting Block Screw Center (2)
309	500781-813	Feed Bar Connecting Block Screw Center Nut (2)
310	507040	Feed Bar Connecting Block Screw Center 500221-803 with 500781-813 (2)
311	170049-803	Feed Lifting Rock Shaft Center (2)
312	140702-830	Feed Lifting Rock Shaft Center Set Screw (2)	YES
313	507039	Feed Bar Connecting Block
314	507063	Feed Bar Connecting Block Shaft Retaining Ring (2)
315	507062	Feed Bar Connecting Block Shaft
316	500223-803	Feed Lifting Rock Shaft Connection Rod Hinge Screw
317	1520-813	Feed Lifting Rock Shaft Connecting Rod Hinge Screw Nut	YES
318	507044	Feed Lifting Rock Shaft
319	896-830	Feed Lifting Rock Shaft Connecting Rod Cap Screw (2)	YES
320	170051	Feed Lifting Rock Shaft Connecting Rod with two 896-830	YES
321	507070-002	Bed Cover Plate (side)(small)
322	507071-002	Bed Cover Plate (side)(large)
323	172139-001	Tension Releasing Lever	YES
324	140563-803	Tension Releasing Lever Hinge Screw	YES
325	12329	Tension Releasing Lever Spring	YES
326	172143	Thread Guide (upper)	YES
327	45345	Slack Thread Regulator and Tension Thread Guide	YES
328	329-852	Slack Thread Regulator and Tension Thread Guide (upper) Screw	YES
329	1440756-830	Tension Stud Set Screw
330	172140	Tension Releasing Pin	YES
331	66774-002	Thread Take-up Spring	YES
332	172226	Tension Disc (3)	YES
333	172228-001	Thread Take-up Spring Thread Guard	YES
334	173669-010	Tension Indicator
335	125314	Tension Spring	YES
336	172218	Tension Indicator Flange Stop Washer
337	172215	Tension Indicator Flange Adaptor	YES
338	906-858	Tension Indicator Flange Adaptor Thumb Nut Cap Set Screw	YES
339	173670-010	Tension Indicator Flange
340	172216	Tension Indicator Flange Adaptor Thumb Nut with 906-858	YES
341	172217	Tension Indicator Flange Adaptor Thumb Nut Cap	YES
342	1792337	Tension Indicator Flange Complete
343	140178	Tension Stud
344	172338	Tension Stud with 140178 and 172337
345	172339	Tension (graduated, adjustable) Complete
346	172306	Thread Pull-off Eyelet
347	172293	Thread Pull-off Eyelet Rivet (2)
348	172185	Disc No. 1 for Arrowhead Stitch (in machine)	YES
349	172195	Bight Amplitude and Pattern Selector and Worm Wheel Shaft Screw Stud	YES
350	172020	Disc Retaining Spring	YES
351	51095-803	Disc (fixed) Clamping Plate Screw (3)	YES
352	172108-001	Disc (fixed) Clamping Plate	YES
353	172114	Disc Driving Worm Wheel	YES
354	172109	Disc (fixed) Position Pin	YES
355	172019	Bight Amplitude and Pattern Selector and Worm Wheel Shaft	YES
356	172204	Disc Set Complete consisting of seven Fixed Discs	YES
357	172115	Disc Driving Worm Wheel 172144 with seven Fixed Discs,	YES
358	140702-830	Bight Amplitude and Pattern Selector and Worm Wheel Shaft Set Screw	YES
359	172017	Bight Amplitude and Pattern Selector	YES
360	172316	Bight Amplitude Control Lever Bracket
361	185-805	Bight Amplitude Control Lever Bracket Screw (2)	YES
362	172315	Bight Amplitude and Pattern Selector Complete 172017,172316, two 185-805
363	140789-819	Bight Amplitude and Pattern Selector Stop Plate Screw (2)	YES
364	172271	Bight Amplitude and Pattern Selector Stop Plate (2)	YES
365	140805-830	Bight Amplitude Control Lever Screw	YES
366	172272	Bight Amplitude Control Lever
367	647-849	Three Pin Terminal Plug (male half) Screw
368	507058	Motor Hold Down Plate
369	141074-819	Motor Hold Down Plate Screw	YES
370	51361-813	Bed Cover Plate (bottom) Screw	YES
371	8879	Bed Cover Plate (bottom) Screw Thumb Nut Washer (felt)	YES
372	51621-813	Bed Cover Plate (bottom) Screw Thumb Nut	YES
373	507008	Bed Cover Plate (bottom) Felt
374	507003-002	Bed Cover Plate (bottom
375	507004-002	Bed Cover Plate (bottom) 507003-002 with 507008
376	172203	Bed Cushion (2)	YES
377	140809-805	Bed Cushion Screw (2)	YES
		FOR INFORMATION
		507082 Arm and Bed (machine Head, ornamented)
		NOTE: Due to the accuracy required for gear alignment, Arm or Bed cannot be supplied separately and can only be sent as a unit, Arm and Bed assembled.
		Accessories
	172187	Fashion Disc 2 – Scallop Stitch
	172189	Fashion Disc 3 – Diamond Stitch
	172190	Fashion Disc 4 – Solid Scallop Stitch
	172191	Fashion Disc 5 – Banner Stitch
	172229	Fashion Disc 6 – Crescent Stitch
	172230	Fashion Disc 7 – Icicle Stitch

The following pictures show the 431G Parts Diagrams:

My 431G came with a messed up zigzag needle plate. Someone had drilled it to accommodate a flat-head screw.

Replacement needle plates for Singer 431G machines are extremely hard to find.

I successfully modified a needle plate from a Singer 700 series machine to fit my 431G.

I ordered a Singer 174198 needle plate from eBay. The ad said it fit models: 750, 756, 758, School 417, 611, 719, 775, and 776.

The plate is very similar to the 431G plate. The holes are in different locations and there is additional material on the back side of the plate. The feed dog slots are also just slightly smaller than the 431G plate.

431G plate (left), 174198 plate (right):

Here is a picture of the plates stacked together.
Stacked Plates

Here is the new plate with changes marked in black.
Marked Plate

I drilled the new plate and sanded the extra material from the rear edge. I used a small diamond grinding bit to expand the feed dog slots and to make a few final adjustments.

The following pictures show the modified plate which fit into the 431G with the new magnetic mount. This is a hand-made prototype so it has a few imperfections but it worked very well. I intend to use this instead of the zigzag plate that came with my machine.

What about the bobbin cover / slide plate?

I compared a slide plate from a Singer 750 series machine to the plate on my 431G. The plate fits the slot in the 431G but the spring hold down is a different length.

The following image is of a 750 slide plate on my 431G sewing machine. It nearly matches the 431G needle plate curve. The 750 slide plate could be ground to fit better.

The following image shows the underside of a 431G slide plate vs. a 750 slide plate. You would need to use a wider hold-down spring to keep the 750 plate down.

The next two images show the profiles for the two different plates. If you trim the 750 plate to fit the 431G, you will lose most of the finger slot.

My 431G Bobbin Cover Spring is difficult to remove without removing the hook. I laid the 750 spring on the outside to determine the relative position to the 431G spring screw. This indicates it may be possible to use a 750 spring and cover plate on a 431G.

The tab on the 750 slide plate must be modified or it won’t slide backward in the 431G slot. You can set it in from the top but the tab is not deep enough to clear the 431G casting when you try to slide it back.

I worked to re-create an uncluttered 431G manual that included the information for chain stitching.

This document is a combination of other information I found online.

I have spent hours cleaning the graphics and re-typing portions of the text to match the original document. I have done my best to update the diagrams and page references.

This should be very close to the original 1963 Singer Manual.

Note: This is a 108-page, color manual. It will take a little time to load.

After you set the machine on its side and remove the bottom cover of the free arm, you can push the needle plate pins out from the underside.

The pin on the right may be obstructed by the feed bar. Adjusting the stitch length to maximum will help you see the hole below the pin.

After loosening the set screws, I used a small drill to push the broken portion of the pin from the hole.

The needle plate pins for these machines were made from spring steel and were commonly broken. Only a few of the German 400 series machines used these pins and replacements are not available.

The following picture shows a with only 3 of the 4 sides of each pin intact.

Magnetic Pin Set – Game Changer

700 series Singer sewing machines use the same diameter pins as the 421G and 431G. On those machines, the needle plate is held on with a magnet that is embedded into the machine case.

I drilled an offset hole in 2mm thick by 10mm diameter neodymium magnets and created replacement stainless steel pins on a metal lathe.

The stainless pins are corrosion resistant, durable and non-magnetic so they will not stick to dressmaker pins.

The solution is simple and it holds extremely well.

Drilling the Magnets

Drilling the magnets is very difficult. I used a carbide glass bit and a lot of coolant to drill mine.

If there is sufficient demand, I would consider making pins for others and having magnets custom made with an offset hole to fit these older machines.

NOTE

When you put a needle plate pin in the hole on the right (closest to the stop motion wheel), you need to be careful not to place it too deeply or it will interfere with the feed dog bar.

Replacement pins need to be two different lengths and the short pin needs to go in the hole on the stop motion wheel side.

Always turn the machine by hand after making modifications to make sure nothing jams.

My original push nut broke when I removed the stitch plate cover from the lid.

I ordered 100 4mm push nuts from McMaster Carr for about $15. These fit the cover and I now have 99 to spare.

I found the easiest way to install these is with a 1/4-inch or 6mm nut driver. It fits over the outside of the push nut and makes it easy to push it down evenly.

I tried a few different solutions for fitting spool pins to my 431G.

The best solution I found was to use double chainring bolts that were designed for bicycle sprockets.

These chainring bolts are 10mm in diameter and have a small 3 or 4 mm hexagonal hole in the top. They fit well in the 431G top.

The attached photo shows similar items on Amazon.

You may have to try a few spool pins to get the correct fit. I just made my own out of HDPE cutting board material on my hobby lathe.

You may have to cut or sand some of the finish off of the inside of the spool pin holes to get the chainring bolts to slide in.

You will need a small spacer to hold the top of the chainring bolts flush with the top of the machine. I bought a nylon bushing at the hardware store and cut slices to fit.

I purchased a 120V Singer 626 on Facebook Marketplace for $40.

All the gears in the machine were melted but the motor, wiring, and foot pedal were in good shape.

The motor fit perfectly in the 431G and the gear pitch was the same so I did not swap the motor gears.

I had to wire the foot pedal into the 431G cord.

I eventually purchased an electronic foot pedal to replace the mechanical one and it worked perfectly.

The stop motion wheel on the 431G is made of plastic and will crack over time.

I tested a stop motion wheel and washer clutch from a Singer 401a and they fit and worked perfectly. If the wheel ever breaks, I can replace it with the metal parts from a Singer 401a.