Liftmaster HCT Overhead Gate Parts
LiftMaster HCT Replacement Parts
Genuine LiftMaster replacement parts for the HCT high-traffic overhead gate operator — the vertical-lift trolley and dolly system that runs a gate up a rail rather than sliding or swinging it. Originally sold as the Hercules. Use the exploded diagram above to find the key number for the part you need, then click any part number in the table below.
Two parts split on build date — February 1999. Check Ref 2 (motor) and Ref 8 (gear reducer): pre-2/99 units take K20-1050B-1RL and K32-50127, post-2/99 units take K20-1050C-1T and K32-50251. The gear box cover at Ref 9 / 10 follows the same split.
Many HCT parts are listed by Q-number. The guide gives a K-number and a Q-number for most items — both appear in the table, and either will find the part.
Two trolley body kits, not one. Ref 15 (Q079) and Ref 25 (Q089) are different assemblies at different points on the chain. Check the diagram before ordering.
Common HCT Repairs
| Symptom | Usual cause | Parts to check |
|---|---|---|
| Gate binds or runs rough up the rail | Dolly or trolley wheels worn | K13-50141 dolly wheels, K11-50136 trolley wheel shaft |
| Chain slack or jumping | Turn buckle out of adjustment, idler sprocket worn | K75-50132 turn buckle kit, K75-50149 idler sprocket |
| Gate overruns its stopping point | Limit nuts drifting on the limit shaft | K13-50140 limit nuts, K11-50139 limit shaft, K23-50099 switch |
| Motor runs but the gate does not lift | Coupling or gear reducer | K75-50130 coupling, K32-50127 / K32-50251 gear reducer |
| Cannot release the gate in a power cut | Chain coupling release or pull ring | K07-50215 coupling release, K80-50145 pull ring |
| Operator dead or resetting itself | Control board, surge protector or reset switch | Q400EHCT board, K70-51060 surge protector, K76-33672 reset |
| Rattle or vibration at the head | Rubber isolators perished | K75-50150 rubber isolator kit |
Gate Operator Repair & Service Parts
| Ref | Part # | Description |
|---|---|---|
| 1 | K80-50044 | Control Board Standoffs, Qty 3 |
| 2 | K20-1050B-1RL | Motor, 1/2 HP, 115V, 1PH, BM |
| 2 | K20-1050C-1T | Motor, 1/2 HP, post 2-1999, Q250 |
| 3 | K29C-65AU2415 | Motor Capacitor, Q027 |
| 4 | K23-50099 | Limit Switch |
| 5 | K09-50124 | Chassis, Q067 |
| 6 | K74-50125 | Control Box, Q068 |
| 7 | K15-41B20GGH | Drive Sprocket, Q070 |
| 8 | K32-50127 | Gear Reducer, 40:1, Q071 |
| 8 | K32-50251 | Gear Reducer, 40:1, post 2-1999 |
| 9 | Q072 | Gear Box Cover |
| 10 | K09-50129 | Gear Box Cover, Q073 |
| 11 | K75-50130 | Coupling, Q074 |
| 12 | K12-50131 | Limit Switch Ball Bearing, Q075 |
| 13 | K75-50132 | Turn Buckle Kit |
| 14 | K11-50136 | Trolley Wheel Shaft, Q078 |
| 15 | K75-50137 | Trolley Body Kit, Q079 |
| 16 | K75-50138 | Dolly Latch Kit, Q080 |
| 17 | K11-50139 | Limit Switch Shaft, Q081 |
| 18 | K13-50140 | Limit Nut, Q082 |
| 19 | K13-50141 | Dolly Wheels, Q083 |
| 20 | K80-50142 | Lock and Keys |
| 21 | K09-50756 | Dolly Cover, Q085 |
| 22 | K87-E-050 | Retaining Ring Clip, Q086 |
| 23 | K80-50145 | Emergency Pull Ring, Q087 |
| 24 | K75-50146 | Arm Assembly, Q088 |
| 25 | K75-50147 | Trolley Body Kit, Q089 |
| 26 | K80-20078 | Plastic Plug, Q090 |
| 27 | K75-50149 | Idler Sprocket, Q091 |
| 28 | K75-50150 | Rubber Isolator Kit, Q092 |
| 29 | K10-50151 | Idler Sprocket Cover, Q093 |
| 30 | K09-50152 | Arm Bracket, Q094 |
| 31 | K77-50153 | Arm Bushing, Q095 |
| 32 | K10-50154 | Head Bracket, Q096 |
| 33 | K10-50155 | Mounting Plate, Q097 |
| 34 | K80-50295 | Access Door Keys, Qty 2, Q118 |
| 35 | K75-50190 | Control Box Cover, Q170 |
| 36 | K07-50215 | Chain Coupling Release, Q200 |
| 37 | Q400EHCT | Control Board, HCT |
| 38 | K29-50279 | Alarm, Q404 |
| 39 | K94-50290 | Wire Harness Kit, HCT Motor, Q620 |
| 40 | K70-51060 | Surge Protector, Q410 |
Parts Not Shown in Diagram
| Ref | Part # | Description |
|---|---|---|
| — | K76-33672 | Reset Switch |