The Rotary S120028 lock ladder is the direct replacement for the Rotary lift it came off of. Cross-referenced as ALS-7544-72, it is the genuine Rotary part — same part number, same fit, and same working specification as the one already on your lift. Ordering the Rotary lock ladder from us gets you the OEM piece that matches the lift, not an aftermarket knock-off that is close but not the same.
Specifications
- Part number: ALS-7544-72
- Brand: Rotary
- Type: Genuine OEM lock ladder
- Fits: AR12, AR123, SM12, SM123
- Lift type: 4-post lift
Restraint gear takes abuse it never shows on the surface. It absorbs the shock every time the lift settles onto the locks, and it's exposed to the same grit, water, and dropped tools as everything else at floor level. Bent teeth, a cracked weld, or a pivot rusted stiff all mean the gear can't do its job. Because it looks like solid steel, people assume it can't wear — and then it does.
Lock ladders and pawls are matched geometry — the tooth pitch, the nose angle, and the mounting have to suit the specific lift. A ladder that almost fits will let the pawl sit shallow on the tooth, which is worse than obvious because it looks engaged and isn't. Match restraint parts to the actual lift model and column, not a close-enough substitute, because the whole point of the part is that it holds under full load.
What lifts this lock ladder fits
This lock ladder fits the lift models below. Click a model to open its visual parts breakdown — the exploded drawing with every part numbered, so you can confirm this is the right part for your exact lift before you order.
- AR12 — see the exploded parts breakdown for this lift
- AR123 — see the exploded parts breakdown for this lift
- SM12 — see the exploded parts breakdown for this lift
- SM123 — see the exploded parts breakdown for this lift
Related parts for this lift
The parts below are commonly ordered alongside this one — cables, sheaves, seals, and hardware wear on similar schedules, and most repairs go faster when the whole set is done in one visit.
Replacing your lock ladder
Replacing a lock ladder or pawl is straightforward mechanical work, but it's the one repair where getting it exactly right isn't optional — the new parts have to let the pawl seat fully into a square tooth and spring home crisply every time. Set it up, then cycle the lift and confirm every lock engages and releases cleanly. Since the locks are what hold a vehicle overhead, the full procedure is worth following start to finish. Full step-by-step: how to replace a lift lock ladder.
Find the right part for your lift
Want to be sure before you buy? Pull the model and serial off your lift's plate and open our Rotary parts lookup to open the exploded parts breakdown for your model — find your part on the drawing and you know it fits. New to finding your model number? our guide to finding your model number covers it, or send a photo of the plate and we will read it for you.
Signs the locking system needs attention
The condemn list for locks: rounded, chipped, or peened ladder teeth; a worn or rounded pawl nose; a pawl that sticks, lags, or won't spring home; a weak or broken return spring; a loose ladder; a release that doesn't pull every pawl together. Any one of these takes the lift out of service — the locks are the last line, and there's no partial credit on the part that catches a falling car.
Parts commonly replaced at the same time
While you are in the locking system, handle the companions: the pawl, its spring, the latch, and the release cable that operates them. Replacing one worn piece and leaving the rest just means uneven locking and another visit. Give us your lift's model and we will build the matched set for both sides.
Safety notes
A lift is only as safe as its locks, and locks are mechanical parts that wear — rounded teeth, tired springs, cables out of adjustment. Replace them at the first sign of uneven or hesitant engagement, verify both sides catch and release in sync, and never park a load on locks you have not tested.
Before you order
Do the lock job once and completely: confirm model and serial, order latch, pawl, spring, and release cable together, and do both columns if either is worn. Even, synchronized locking depends on matched hardware. Call and we will confirm the right kit for your lift before it ships.
Check your lift's serial before ordering
The most common reason a lift part comes back is not a defect — it is a revision mismatch. Manufacturers change sub-parts between production runs while keeping the same lift model name, so "it fits my lift model" is not always enough. The model plate carries the serial number that pins your lift to a specific run, and that is the number that settles which version of this part belongs on your lift.
Can't find the plate? Measure the old part — overall length, bolt-hole spacing, thread size on anything threaded — and photograph it from a couple of angles. Send that with your lift's brand and rough age and we will match it against the parts breakdowns we service from every week.
Why buy your Rotary lock ladder from Auto Lift Services
We install, inspect, and repair Rotary lifts every week — the ALS-7544-72 is a part we handle in the shop, not a random SKU we drop-ship. The phone answers if you have a question mid-install — call 800-674-9302 — and every part ships genuine, no aftermarket substitution unless you ask for it.
Lock Ladder - Rotary S120028
Parts that fit your lift
This Rotary part fits the lift models below. Click your model to see every part that fits it — handy for grabbing the wear items that usually go at the same time (cables, sheaves, pins, locks).
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