Liftmaster K74-40347, LIMIT SWITCH KIT
The Liftmaster K74-40347, LIMIT SWITCH KIT is a LiftMaster replacement Limit switch kit used to restore the correct mechanical or electrical housing, drive, or service assembly on the matching operator. This is the type of part that should be selected by the operator model number and the LiftMaster replacement parts diagram, not by appearance alone. Similar LiftMaster and Elite service parts can look close in photos while using different mounting points, wiring locations, sprocket sizes, switch layouts, or enclosure dimensions.
For a service technician or parts-counter check, the important question is whether the original operator calls for K74-40347 or one of the related numbers listed below. When the correct part is used, it helps protect the operator assembly, maintain proper chain or switch alignment, or restore the intended electrical function without forcing a substitute part into the system. If the original part is damaged from impact, corrosion, water intrusion, heat, worn bearings, chain misalignment, or electrical failure, inspect the surrounding parts before installing the replacement so the same failure does not repeat.
Compatible With
This part is commonly associated with the following LiftMaster applications when confirmed by model number, configuration, and the replacement parts diagram:
- LiftMaster SL390 slide gate operators
- SL930 heavy-duty commercial DC slide gate operator parts diagrams showing K74-40347 service kit
- related slide gate operators only when the limit switch plate, actuator plate, and wiring match the parts diagram.
Important Compatibility Notes
Limit switch kits are model- and generation-sensitive. Confirm switch layout, actuator plate, mounting plate, wiring, and diagram callout before ordering.
Features & Specifications
| Feature / Specification | Details |
|---|
| Manufacturer | LiftMaster |
| Product Type | Limit switch kit |
| Part Number | K74-40347 |
| Application | Open/close travel limit switch service |
| Compatible Operator Type | Commercial slide gate operator |
| Included Components | Limit switch plate, switches, actuator plate, grommet, screws, nuts as commonly listed |
| Notes | Limit adjustment and safety testing are required after replacement. |
Also Known As / Related Part Numbers
The following numbers and search variations may be associated with this item, but related numbers should not be treated as automatic replacements unless confirmed by the manufacturer parts diagram:
- K74-40347
- 74-40347
- LM-K74-40347
- LiftMaster K74-40347
- limit switch kit
- service kit limit switch
- SL390 limit switch kit
- SL930 limit switch kit
Technician Note
Before replacing this part, inspect the connected hardware, wiring, mounting points, chain path, limit system, enclosure seal, and operator structure as applicable. A failed service part is often the visible result of another issue such as gate drag, poor alignment, water entry, worn chain, loose hardware, or damaged wiring.
Before Ordering Checklist
- Confirm the exact LiftMaster model number from the operator label.
- Compare the original part number, shape, mounting points, and service diagram callout.
- Check whether the operator is an older, UL, UL325, solar, metal-box, plastic-box, AC, DC, or heavy-duty generation.
- Verify that related part numbers are true matches and not just similar catalog references.
- For electrical parts, disconnect power and batteries before service and use a qualified technician when needed.
Professional Advisory
Gate operators are safety-related systems. Do not bypass monitored safety devices, limit systems, protective covers, or electrical protection to make a part fit. If the operator has unsafe movement, damaged wiring, failed safety devices, or high-voltage concerns, have the system inspected by a qualified gate technician.
Product Questions & Answers
What does the K74-40347 limit switch kit control?
It is used in the gate travel limit system so the operator can identify the open and close stopping points.
Which models commonly use K74-40347?
K74-40347 is listed for SL390 slide gate operators and appears in SL930 heavy-duty DC slide gate parts references.
What symptoms can point to a limit switch problem?
Symptoms can include overtravel, stopping short, failure to stop at the correct position, or visible damage to the switch, bracket, or actuator plate.
Does the gate need to be adjusted after installation?
Yes. Limit settings and full gate travel should be adjusted and tested after replacement. Safety devices must remain connected and working.
Can this be installed without checking the parts diagram?
No. Similar limit switch kits can look close but use different brackets, actuator plates, or wiring layouts. Confirm K74-40347 before ordering.
