LiftMaster 81C168 Screw Drive Rack
The LiftMaster 81C168 rack, also listed as K081C0168, is a screw drive rack replacement kit for select LiftMaster and Chamberlain screw drive garage door openers. It is part of the carriage/trolley drive connection and helps transfer motion from the screw rail to the door assembly.
This rack is not compatible with LiftMaster 3130 or 3240 models. Those applications are directed to K081C0275 / 81C275, so the model split should be checked carefully before ordering.
Features & Specifications
| Feature / Specification | Details |
|---|
| Manufacturer | LiftMaster / Chamberlain |
| Product Type | Screw Drive Rack |
| Part Number | 81C168 / K081C0168 |
| Application | Replacement rack for screw drive carriage/trolley assemblies |
| Compatible Operator Type | Select LiftMaster / Chamberlain screw drive garage door openers |
| Compatibility | Use K081C0275 / 81C275 for 3130 and 3240 |
| Includes | Rack replacement kit |
| Notes | For many screw drive applications; not for 3130 or 3240 |
Also Known As / Related Part Numbers
- K081C0168
- 081C0168
- 81C168
- Screw Drive Rack
Technician Note
The 81C168 and 81C275 racks are easy to confuse. For LiftMaster 3130 or 3240, use K081C0275 / 81C275 instead of K081C0168 / 81C168.
Before Ordering Checklist
- Confirm the opener is a screw drive model.
- Check whether the model is 3130 or 3240 before ordering.
- Inspect the trolley/carriage assembly for wear.
- Check screw rail lubrication and condition.
- Correct door balance or binding before installing a new rack.
Professional Advisory
A stripped rack can be a symptom of a heavy or binding garage door. If the door is hard to move by hand or the opener strains, have the door system inspected by a qualified technician.
Product Questions
What does the 81C168 screw drive rack do?
The 81C168 rack engages with the screw drive carriage assembly so the opener can transfer motion through the screw rail.
Is 81C168 the same as K081C0168?
Yes. K081C0168 is the current formatted part number, and 81C168 is the common short number.
Does 81C168 fit LiftMaster 3130 or 3240?
No. LiftMaster directs 3130 and 3240 models to K081C0275 / 81C275 instead.
What symptoms suggest a worn screw drive rack?
The opener may run while the door does not move properly, or the carriage may chatter, slip, or fail to stay engaged.
Should the rail and trolley be inspected too?
Yes. A worn rack can be related to trolley wear, dry screw rail operation, door binding, or a damaged coupler.
