LiftMaster K75-50090 Idler Pulley Replacement Kit for SL3000 Slide Gate Operators
The LiftMaster K75-50090 is an idler pulley replacement kit used in the drive system of select SL3000 series commercial slide gate operators. In the operator, this pulley assembly supports the chain path and helps keep the chain aligned as the gate opens and closes.
This is a mechanical wear part that is commonly replaced when the chain path becomes noisy, the idler sprocket is damaged, the bushing is worn, or the chain no longer tracks smoothly. Because commercial slide gate operators operate under load, the pulley, chain, sprockets, and mounting hardware should be inspected together before replacing only one component.
What This Part Does
The idler pulley guides and supports the drive chain so the slide gate operator can transfer motion smoothly from the drive system to the gate. Proper chain alignment reduces side loading, chain wear, and stress on the operator shaft and sprocket components.
This kit is typically used during chain-drive service, idler sprocket replacement, or repair after chain misalignment. If the gate is dragging, the chain is too tight, or the gate hardware is worn, those issues should be corrected before putting the operator back into service.
Common Symptoms and Service Use
- Noisy or uneven chain movement
- Visible wear on the idler sprocket or bushing
- Chain jumping, rubbing, or tracking poorly
- Loose or missing idler pulley hardware
- Preventive replacement during SL3000 drive-system service
Compatible With
The K75-50090 is commonly used with LiftMaster and Elite SL3000 series slide gate operator applications. Some listings also tie the Q013 idler sprocket assembly to related LiftMaster slide gate families, but exact fit should be verified by the operator parts diagram.
Common Compatible Products and Operator Families
- LiftMaster SL3000 commercial slide gate operators
- LiftMaster SL3000U slide gate operators when confirmed by parts diagram
- LiftMaster SL3000UL slide gate operators when confirmed by parts diagram
- Elite SL3000 slide gate operators
- Elite SL3000UL slide gate operators
- SL3000 chain-drive assemblies using Q013 idler sprocket references
- Select LiftMaster slide gate operators where K75-50090 is shown in the parts breakdown
Additional Applications to Verify
- Some aftermarket listings associate Q013 with CSL24 and RSL12 series operators; verify carefully by current parts diagram before listing as confirmed
- Service applications where the original idler pulley is marked Q013 or K75-50090
Important Compatibility Notes
- This kit is not a universal idler pulley for all LiftMaster slide gate operators.
- Confirm chain size, mounting hardware, shaft/bushing fit, and pulley location before ordering.
- If the gate is binding or the chain is over-tightened, a new idler pulley may wear out quickly.
Features & Specifications
| Feature / Specification | Details |
|---|
| Manufacturer | LiftMaster |
| Product Type | Idler pulley replacement kit |
| Part Number | K75-50090 |
| Related Number | Q013 |
| Application | Chain idler pulley service on select slide gate operators |
| Compatible Operator Type | Select SL3000 series commercial slide gate operators |
| Typical Contents | Idler sprocket pulley, bushing, hex screw, hex nut, and washers when supplied as a complete kit |
| Notes | Verify exact kit contents and parts diagram before ordering. |
Also Known As / Related Part Numbers
This part may be searched under several part-number formats, older listing numbers, catalog references, or related component numbers. Related numbers are included to help identify the correct item, but they should not be treated as interchangeable unless the operator parts diagram supports the match.
- K75-50090
- Q013
- 75-50090
- 7550090
- K7550090
- Elite Q013
- LiftMaster Q013 idler sprocket
- LiftMaster SL3000 idler pulley kit
- LiftMaster idler sprocket assembly
Technician Note
Inspect the chain, drive sprocket, gate rollers, chain brackets, and gate alignment before replacing the idler pulley. A damaged idler is often a symptom of chain misalignment, excessive chain tension, or a gate that is dragging on the track.
Before Ordering, Confirm
- The operator is an SL3000 series slide gate operator or the parts diagram calls for K75-50090 / Q013.
- The original pulley location and hardware match the replacement kit.
- The chain size and chain path are correct.
- The gate rolls freely and is not forcing the operator to carry excessive load.
- The kit contents match what is needed for the repair.
Professional Advisory
Disconnect power before servicing the slide gate operator. Mechanical drive components can pinch or pull hands, tools, and clothing into the chain path. After replacement, chain tension, sprocket alignment, gate travel, and all safety devices should be tested before the operator is returned to service.
Important Ordering Warnings
- Do not substitute a pulley with a different bore, tooth profile, or mounting arrangement.
- Do not run the operator with loose chain, missing guards, or damaged idler hardware.
- K75-50090 and K17-50095 are both SL3000-related pulley parts, but they are different components and should not be interchanged.
Questions & Answers
What is included with the K75-50090 kit?
Common listings describe the kit as including the idler sprocket pulley, bushing, hex screw, hex nut, and washers, but package contents should be confirmed before shipment.
What operators commonly use K75-50090?
K75-50090 is commonly associated with LiftMaster and Elite SL3000 series commercial slide gate operators.
Is K75-50090 the same as Q013?
Yes, Q013 is commonly listed as an also-known-as or related number for the K75-50090 idler pulley assembly.
Can this fix a noisy slide gate operator?
It can help if the noise is caused by a worn or damaged idler pulley, but chain tension, sprocket alignment, rollers, and gate condition should also be checked.
Is this the same as the K17-50095 gear pulley?
No. K75-50090 is an idler pulley kit, while K17-50095 is a gear pulley associated with the SL3000 drive system.
