Sany Telescoping Mechanism

The Sany Telescoping Mechanism is a complete OEM extension and retraction system that powers the multi-section boom movements on Sany STC-series truck cranes and SAC-series all‑terrain cranes.

This Sany Telescoping Mechanism integrates boom ropes, pulley covers, guide wheel brackets, precision pins, shafts, and all necessary fasteners into a single factory‑matched assembly. When you need authentic replacement components, trust Sany Parts to deliver factory-original quality and precise fitment.

The Sany Telescoping Mechanism is specifically designed for Sany cranes with 4-section or 5-section telescopic booms, ensuring smooth, synchronized extension and retraction for superior lifting efficiency and operational safety.

Sany Telescoping Mechanism — OEM boom extension and retraction system for Sany heavy truck cranes and all‑terrain cranes

What is the Sany Telescoping Mechanism?

The Sany Telescoping Mechanism is the core actuation system that controls the extension and retraction of multi-section boom assemblies on Sany heavy lifting machinery. This mechanism works in conjunction with hydraulic cylinders and rope systems to ensure all boom sections move smoothly and synchronously during operation.

The Sany Telescoping Mechanism assembly comprises 22 precision‑engineered components that function as an integrated extension and retraction system. Withdrawing ropes manage retraction movements, while extending ropes control the outward movement of each boom section. Cover plates protect internal components, guide wheel brackets ensure smooth rope travel, and precision pins maintain correct alignment between boom sections.

The Sany Telescoping Mechanism can be classified into two main types based on the number of boom sections. Synchronous telescoping uses a two‑stage wire rope row driven by a first‑stage telescopic cylinder, applicable to 4‑section booms on models such as STC200S and QY25. Sequential and synchronous telescoping uses a double‑stage telescopic cylinder, applicable to 5‑section booms on models such as STC250S, STC250H, and STC750S.

The Sany Telescoping Mechanism is a direct replacement for worn or damaged rope systems on Sany STC‑series truck cranes and SAC‑series all‑terrain cranes. By using this genuine assembly, you ensure that rope tensions and alignment match factory specifications, eliminating uneven extension speeds and reducing the risk of rope jumping off pulleys during lifting operations.

Product Parameters of Sany Telescoping Mechanism

Technical specifications: The Sany Telescoping Mechanism is engineered for cranes with 4‑section or 5‑section telescopic booms. The rope system uses high‑strength steel wire ropes with extension and retraction ropes working in opposition to achieve synchronized boom movement.

The mechanism typically operates in conjunction with two or three telescoping cylinders for 4‑section booms, and with two inverted cylinders for 5‑section booms such as STC250S and STC250H. All components of the Sany Telescoping Mechanism are manufactured under ISO 9001:2025 certification and are 100% traceable to original production batches.

The Sany Telescoping Mechanism has been validated on Sany STC and SAC series cranes operating in Australian mines, Chilean copper mines, and Canadian oil sands, demonstrating a field service life exceeding 10,000 operating hours under heavy‑duty lifting conditions when properly maintained.

Why Choose Our Sany Telescoping Mechanism?

Complete 22‑Component OEM Kit — Perfectly Matched Components: The Sany Telescoping Mechanism includes every rope, bracket, cover, pin, and fastener as a single, factory‑matched assembly. This eliminates compatibility problems that arise from sourcing individual components from different suppliers. The extension and retraction ropes are precisely matched to the boom section lengths, ensuring synchronized movement and eliminating the uneven extension speeds common with mismatched aftermarket rope sets.

Engineered for Synchronized Multi‑Section Telescoping: The Sany Telescoping Mechanism is designed for both synchronous and sequential telescoping applications. For 4‑section booms, the two‑stage wire rope row provides simultaneous extension of all sections. For 5‑section booms, the double‑stage cylinder with dual inverted cylinders provides sequential extension with precise section‑by‑section control. This engineering approach maximizes lifting efficiency while maintaining structural integrity at every boom length.

Superior Rope Management with Guide Wheel Brackets: The Sany Telescoping Mechanism includes precision guide wheel brackets (10649337) and pulley covers (10048536) that maintain proper rope alignment within the boom structure. These components ensure that extension and retraction ropes travel smoothly without contacting internal boom surfaces, reducing friction and extending rope service life. The pulley shell (11264966) provides additional rope guidance at the boom tip.

Fleet‑Proven Reliability and Comprehensive Warranty: The Sany Telescoping Mechanism is standard equipment on Sany STC‑series truck cranes and SAC‑series all‑terrain cranes in over 100 countries. Fleet data shows that genuine Sany telescoping mechanisms deliver an average service life exceeding 10,000 operating hours—three times longer than generic aftermarket assemblies—while eliminating rope fraying incidents and uneven boom extension failures. The assembly is backed by a 24‑month manufacturer’s warranty covering rope breakage, bracket cracking, and pulley failure. Volume pricing, consignment stock, and global technical support are available for large fleets.

What are the Routine Maintenance Considerations for the Sany Telescoping Mechanism?

Daily visual inspection before operation: Before each shift, inspect the Sany Telescoping Mechanism for visible rope fraying, broken strands, or uneven rope tension. Remove the access covers and inspect the extension ropes (10212934, 10583247) and withdrawing ropes (10130780, 10130769) for any signs of kinking, corrosion, or wire breakage. Check the guide wheel bracket (10649337) for wear or damage. Also inspect the pulley shell (11264966) for any visible groove wear or deformation.

Rope tension check and adjustment — every 250 operating hours: The Sany Telescoping Mechanism requires proper rope tension for synchronized boom extension. Extend the boom partially and check the tension of all extension and retraction ropes. If any rope is loose, adjust using the adjusting nuts provided on the rope ends. Refer to the crane service manual for specific tension specifications. Uneven rope tension will cause sections to extend at different speeds, leading to internal boom contact and accelerated wear.

Guide wheel and pulley inspection — every 500 operating hours: Inspect the guide wheel bracket (10649337) for bearing wear or seized rollers. The guide wheels must rotate freely to maintain proper rope alignment. Check the pulley shell (11264966) for groove wear—if the groove has worn to a depth that reduces the rope contact angle by more than 15 degrees, replace the entire pulley shell assembly. Verify that all cover plates (10048450) are securely fastened and free from cracks.

Preventative replacement schedule — every 4,000 hours or 2 years: For high‑use cranes, Sany recommends a full replacement of the Sany Telescoping Mechanism every 4,000 operating hours or 2 years. Replace both extension and retraction ropes as a set—mixing new and old ropes results in uneven tension and accelerated wear. Replace the guide wheel bracket, pulley shell, and all cover plates. Replace all nuts (A210319000005, A210307000005) and washers, as thread locker effectiveness degrades with age. Keep a detailed maintenance log tracking rope tension measurements, guide wheel condition, and pulley wear. By following this proactive schedule, the Sany Telescoping Mechanism can reliably exceed 10,000 operating hours.

The extending ropes (10212934 for 5th section, 10583247 for 4th section) are high‑strength steel wire ropes that pull the outer boom sections outward during extension. These ropes are anchored at one end to the telescoping cylinder and at the other end to the movable boom section. As the cylinder extends, the extension ropes pull the sections outward in sequence.

The withdrawing ropes (10130780 for 5th section, 10130769 for 4th section) are the counterpart ropes that retract the boom sections. These ropes are crossed from the cylinder to the boom sections, so they become taut during retraction and slack during extension. The rope diameter is typically 12‑16 mm depending on crane capacity, with a minimum breaking load exceeding 100 kN.

The guide wheel bracket (10649337) directs the extension and retraction ropes through the boom structure, preventing contact with internal surfaces. The bracket houses sealed ball bearings that should be lubricated every 250 operating hours. If a guide wheel seizes, the rope will abrade against the bracket, leading to rapid rope failure. If any guide wheel does not rotate freely, replace the entire bracket assembly immediately.

The pulley shell (11264966) is mounted at the boom tip and guides the hoist ropes, not the telescoping ropes. However, it is included in the Sany Telescoping Mechanism because it shares mounting hardware with the telescoping system. The pulley shell features a hardened groove surface that resists wear from the hoist rope. If the groove wears more than 15% of the rope diameter, replace the pulley shell to prevent uneven rope wear.

The cover plates (10048450) protect the internal telescoping mechanism components from dust and debris. These covers should be removed during each rope tension check and reinstalled securely afterward. If a cover plate is cracked or missing, replace it immediately—debris entering the boom can accelerate rope wear and cause premature failure.

For Sany cranes operating in extreme cold climates (below -25°C), special considerations apply to the Sany Telescoping Mechanism. Steel wire ropes become more brittle at low temperatures; avoid shock loading or sudden boom movements that could cause rope fracture. The ropes may contract slightly in cold conditions, reducing tension; check and adjust rope tension after the crane has been operating for 30 minutes. Guide wheel bearings may require low‑temperature grease; use lithium‑based grease rated for -40°C. Extend and retract the boom slowly several times before full operation to warm the ropes and bearings.

The Sany Telescoping Mechanism is also available as part of a complete boom system overhaul kit, which includes all telescoping ropes, guide wheel brackets, pulley shells, cover plates, and all mounting hardware. Sany recommends this complete‑kit approach for vehicles with over 8,000 operating hours, as it allows the entire telescoping system to be renewed in a single service event, eliminating the risk of hidden rope fatigue or guide wheel bearing wear that could lead to catastrophic failure.

Fleet managers using this strategy report a 50% reduction in telescoping mechanism‑related breakdowns and a 40% reduction in total boom system maintenance costs over the equipment’s life.

Contact our parts specialists through the Get Quotation button above for custom kit configurations tailored to your fleet’s specific needs.