Most tower crane breakdowns are not caused by the big steel structure. They are caused by small wear parts that were left too long: a pin with elongated holes, a pulley with a worn groove, a brake disc that no longer grips, a limit switch that no longer trips. This guide covers the parts that wear first, what to look for, and what to confirm before you order.
1. Pins and headed shafts
Pins connect mast sections, jib sections and other assemblies, and they take repeated shear and impact loads. Check them when the crane is serviced, and especially after any overload or hard stop.
Warning signs:
- Elongated or oval pin holes in the mating part
- Visible wear steps or scoring on the pin surface
- A pin that fits loosely where it used to fit snugly
- Missing or damaged retaining clips
When ordering, confirm the pin diameter, length and head type, and the part number if it is stamped on the old pin. A pin that is close in size is not good enough — the diameter and fit must match.
2. Pulleys and sheaves
Steel and nylon pulleys guide the hoist, trolley and luffing ropes. A worn groove damages the rope, and a damaged rope then damages everything else it runs over.
Warning signs:
- A groove worn off-centre or with sharp edges
- Cracks, chips or flat spots, especially on nylon pulleys
- A pulley that wobbles, sticks or does not rotate freely
- Rope wear that lines up with one particular pulley
When ordering, confirm the pulley diameter, groove size, bore and bearing type, and whether it is a steel or nylon pulley. Send a photo of the old pulley and its part number if you have it — that is usually faster than describing it.
3. Brake discs and brake parts
Brake discs on hoist, trolley and slewing motors must stop the load reliably every time. Brake wear is gradual, which makes it easy to miss until stopping distances grow.
Warning signs:
- Longer stopping distances or load drift after braking
- Scoring, glazing or heat discoloration on the disc surface
- Unusual noise or vibration during braking
- A disc worn close to its minimum thickness
Never fit a brake disc by diameter alone. Confirm the motor type, disc thickness, bolt pattern and, where applicable, the part number stamped on the old disc.
4. Limit switches and safety devices
Limit switches, overload limiters and anemometers are safety parts, not convenience parts. A faulty limit switch can allow a hook, trolley or slew movement to run past its safe limit.
Warning signs:
- A movement that does not stop where it used to
- A switch that trips late, intermittently, or not at all
- Damaged housings, cables or actuator arms
- False alarms from an overload or moment limiter
Test safety devices on a schedule, not only when something goes wrong, and replace a suspect switch rather than adjusting around it.
5. Wire ropes and hook blocks
Wire rope wear shows as broken wires, corrosion, kinking or diameter loss. Follow the crane manual and local rules for discard criteria — when in doubt, replace the rope. Hook blocks should be checked for hook deformation, latch damage and sheave wear at the same time.
A simple inspection routine
- Walk the crane at each scheduled service and check pins, pulleys and brakes first.
- Photograph anything worn and note the part number where visible.
- Order replacements before the part fails, not after — stock parts can often ship quickly, while a breakdown order cannot wait for production.
- After fitting, test the movement under no load, then under a normal load, before returning the crane to full work.
FAQ
Which tower crane parts wear out fastest?
Pins, pulleys, brake discs, limit switches and wire ropes are the usual wear items. Their life depends on duty cycle, environment and maintenance, so there is no single mileage figure that fits every crane.
Can I replace a worn part with a different brand?
Yes, if the replacement matches the original dimensions, connection details and rating. Compatibility is decided by measurements and part numbers, not by brand name alone.
How do I identify a part with no visible part number?
Send clear photos of the part, its mating parts and any markings, plus the crane brand and model and the mast or motor type if known. A supplier can usually identify it from those details.
Should I keep spare wear parts on site?
For cranes in continuous use, keeping common pins, a spare pulley, brake parts and limit switches on site avoids days of downtime for a small part.
HERO CRANE (Shenyang Hero Equipment) supplies tower crane wear and spare parts — pins, pulleys, brake discs, limit switches, motors and more — for export worldwide. Contact us with your crane model or old part photos to confirm fit before ordering.