Tensor de correa 3976832 3911621 para motor Cummins 4B3.9 6B5.9 6C8.3 B5.9 ISB <td>.9 </td>.9 {{ZKF_2}}.9 Excavadora Hyundai {{ZKF_3}}-7 {{ZKF_4}}-3 {{ZKF_5}}-7

Product Specifications

Compatible Models

Tired of Belt Slippage and Engine Overheating? Get the Right Cummins Belt Tensioner 3976832 for Your Hyundai R305LC-7 or QSB5.9 Engine

Every hour your excavator sits idle due to belt misalignment or tension loss costs hundreds in lost productivity — especially on tight infrastructure deadlines. Counterfeit tensioners fail within weeks, causing pulley wear, alternator drop-out, and engine overheating. OEM replacements take 3+ weeks to arrive and cost up to 45% more than verified aftermarket alternatives.

OEM-Equivalent Quality, Ready to Ship from Guangzhou Warehouse

This Cummins belt tensioner is engineered to match original torque specs and pivot geometry for engines including 4B3.9, QSB5.9, and ISB CM550. Backed by 10 years of global export experience, we source exclusively from ISO-certified factories and test every batch for spring force retention, bearing rotation resistance, and arm deflection under load — critical for continuous-duty applications like hydraulic pump drive systems.

Where This Part Works

Used across construction sites, quarries, ports, and municipal public works fleets, this tensioner maintains consistent belt engagement during high-vibration digging cycles and variable-load engine operation. It directly supports accessory drives powering cooling fans, air compressors, and hydraulic pumps — making correct fit and preload accuracy essential for thermal management and system reliability on machines like the Hyundai R305LC-7 and HL740-9B.

Engineering Details That Matter

The tensioner arm is precision-forged from SAE 1045 steel and induction-hardened to 52–56 HRC for fatigue resistance at pivot points. Its sealed deep-groove ball bearing meets ISO 15243 standards for contamination resistance and rated life >10,000 hours. The automatic spring mechanism uses calibrated torsion steel with ±3% force tolerance to maintain 45–55 Nm static tension across temperature ranges from –20°C to +110°C. Dimensional tolerances are held to ±0.15 mm per ASME Y14.5 GD&T standards, ensuring full interchangeability with OEM mounting brackets and pulleys.

The Real Cost of Wrong Parts

A $35 counterfeit tensioner may save upfront, but risks $1,200 in labor for repeated fan belt replacement, $800 in radiator damage from overheating, and $3,000+ in daily downtime for a mid-size excavator fleet. Our Cummins 4B3.9 engine tensioner meets all OEM dimensional and performance benchmarks per Cummins Bulletin 400-1137, reducing total cost of ownership through extended service intervals and predictable failure modes. This is not just a part — it’s a reliability multiplier for your powertrain.

Why Customers Trust XUNPO

Packaging & Shipping

• Individually sealed in anti-corrosion packaging with foam inserts inside reinforced export cartons
• In-stock items ship within 2–5 working days after order confirmation
• Flexible logistics: DHL/FedEx/UPS express, air freight, or sea freight available
• Real-time tracking number provided upon dispatch
• Minimum order quantity: 1 piece — no bulk requirement for urgent repairs

Get Your Cummins Belt Tensioner Now

Your machine isn’t generating revenue while waiting. Send us your part number (e.g., 3976832 or 3911621), machine model (e.g., Hyundai R305LC-7), and required quantity — we’ll reply with a competitive quote within 24 hours. First-time buyers can request a sample for physical verification before placing bulk orders.

Frequently Asked Questions