Liftmaster SW490 & SW490GL Swing Gate Parts
LiftMaster SW490 & SW490GL Replacement Parts
Genuine LiftMaster replacement parts for the SW490 and SW490GL commercial swing gate operators — the heaviest of the SW4 series, driving the gate through a rigid extension arm and a #50 chain. Use the exploded diagram above to find the key number for the part you need, then click any part number in the tables below to go straight to that product.
The diagram is grouped into lettered assemblies. A is the arm extension kit, D is the drive assembly and E is the electrical panel. Those lettered refs match the drawing exactly.
Single or double swing? D13 is the single-swing collar (75-G0400) and D14 is the double-swing collar (75-G0401). Ordering the wrong one is the most common mistake on this operator.
Match the overload to the motor, not the operator. E4 runs from 6A to 20A plus a 4.0–6.0A option — read the amp rating off the existing overload before ordering.
The housing and control box parts (1–14) are shared with the SW470 and are numbered as printed in the guide's list.
Common SW490 Repairs
| Symptom | Usual cause | Parts to check |
|---|---|---|
| Motor runs but the gate does not move | Drive belt slipping or chain worn | K16-4L280 belt, K19-2075 chain, K19-50ML master link |
| Gate overruns or stops short | Limit switch or collar slipping on the shaft | K23-2016 limit switch, 75-G0400 / 75-G0401 collar |
| Trips the overload repeatedly | Overload sized wrong or failing | K25-2006 to K25-2020 overloads, K25-4006-D |
| Operator dead, no board lights | Transformer, relay or contactor | K21-3260-1 transformer, K24-115-1 relay, K03-8024-K contactor |
| Erratic travel or missed counts | Hall effect sensor | K74-18382 hall effect sensor kit |
| Play or knocking at the arm | Bearing sleeve or rod end worn | K12-10172 bearing sleeve, 08-2001 rod end fitting |
| Grinding from the drive train | Gear reducer, bearing or sprockets | K32-2001 gear reducer, K12-2125 bearing, K15-2002 sprocket |
| No warning tone before the gate moves | Alarm kit | K74-18655 alarm kit |
Arm Extension Kit (A)
| Ref | Part # | Description |
|---|---|---|
| A | K75-18366 | Arm Extension Kit, SW490 |
| A1 | 08-2001 | Rod End Fitting |
| A2 | 10-2011 | Gate Bracket |
| A3 | 70-18618M | Extension Arm — no longer available |
| A4 | 10-3900 | Galvanized Tube, 39" x 1" ID x 1-5/16" |
| A5 | K12-10172 | Bearing Sleeve, 1" |
| A6 | 07-2103M | Arm Stop |
| A7 | 06-2025 | Actuator Arm Assembly — no longer available |
Drive Assembly (D)
| Ref | Part # | Description |
|---|---|---|
| D | K75-18367 | Drive Assembly Kit |
| D1 | 10-2008 | Switch Bracket — no longer available |
| D2 | K10-G0539 | Sensor Bracket |
| D3 | K12-2125 | Flanged Ball Bearing, 1-1/4" Bore |
| D4 | K15-2002 | Sprocket, 50B60T |
| D5 | 15-50B12LGH | Sprocket, 50B12, 1" |
| D6 | K16-4L280 | Belt, 3L280 |
| D7 | SW008 | Reducer Pulley, 2", 5/8" Bore |
| D8 | K17-2701 | Pulley, 7" x 5/8" |
| D9 | K19-2075 | Chain, #50 x 75, No ML |
| D10 | K19-50ML | Master Link, #50 |
| D11 | K23-2016 | Limit Switch |
| D12 | K32-2001 | Gear Reducer |
| D13 | 75-G0400X | Collar |
| D14 | 75-G0401X | Collar, Double Swing |
| D15 | K74-18382 | Hall Effect Sensor Kit |
| D16 | K84-DT-06 | Nut, 6-32, Tinner-Man |
| D17 | K31-2712 | Spacer |
| D18 | 80-207-19 | Key, 1/4" x 1/4" x 1-1/2" |
| D19 | K80-207-23 | Keyway |
| D20 | K80-207-25 | Keyway |
Electrical Panel (E)
| Ref | Part # | Description |
|---|---|---|
| E1 | K03-8024-K | Reversing Contactor |
| E2 | K21-3260-1 | Transformer, 120/208/230/460, 60VA |
| E3 | K24-115-1 | Relay, 120V, 10A |
| E3 | K24-230-5 | Relay, 3PDT, 230V, 7A |
| E4 | K25-2006 | Overload, 6A |
| E4 | K25-2008 | Overload, 8A |
| E4 | K25-2010 | Overload, 10A |
| E4 | K25-2015 | Overload, 15A |
| E4 | K25-2020 | Overload, 20A |
| E4 | 25-4002-5 | Relay, Overload, 1.6-2.5A — no longer available |
| E4 | K25-4006-D | Overload, 4.0-6.0A |
Housing and Control Box
| Ref | Part # | Description |
|---|---|---|
| 1 | 10-2013 | Mounting Bracket |
| 2 | 10-2103-T | Reducer Bracket — no longer available |
| 3 | 10-2104-T | Motor Bracket — no longer available |
| 4 | K10-G0326 | Switch Box Cover |
| 5 | 10-G0387 | Sensor Support Bracket — no longer available |
| 6 | K23-3001 | On/Off Switch, 125/277VAC, 20A |
| 7 | K74-18382 | Hall Effect Sensor Kit |
| 8 | K74-18655 | Alarm Kit |
| 9 | 10-18461 | Side Cover |
| 10 | K001A5566 | GL Control Board |
| 11 | K21-3260-1 | Transformer, 120/208/230/460, 60VA |
| 12 | K23-2016 | Limit Switch |
| 13 | K29-10338 | Motor Capacitor |
| 13 | K29-12110 | Capacitor, 20uF, 230V |
| 14 | K03-8024-K | Reversing Contactor |