<p>Keep your Cummins 6C, ISB, or QSB engine running at peak performance with our <strong>Belt Tensioner Assembly 3936213</strong>—designed to maintain optimal belt tension and prevent costly downtime. This ISO-certified replacement fits 4B3.9, 6B5.9, and other Cummins models, directly replacing OE part numbers 5259022 and 3976831 for seamless installation.</p><ul><li>Precision-engineered spring mechanism ensures consistent tension under extreme operating conditions</li><li>Durable bearing assembly reduces friction and extends service life in high-vibration environments</li><li>Ready to install with all necessary hardware, minimizing maintenance delays for your fleet</li></ul>
| Parameter | Details |
|---|---|
| Part Name | Belt Tensioner Assembly |
| Replacement Part Number | 3936213, 5259022, 3976831 |
| Compatible Engine Brand | Cummins |
| Engine Models | 6C, ISB, QSB, 4B3.9, B4.5, 6B5.9, B6.7, 4B, 6B, ISC, QSC, ISL, QSL |
| Quality Certification | ISO-certified |
| Condition | New Aftermarket |
| Warranty | 3–12 month warranty against manufacturing defects |
| Brand | Applicable Models |
|---|---|
| Cummins | 6C, ISB, QSB, 4B3.9, B4.5, 6B5.9, B6.7, 4B, 6B, ISC, QSC, ISL, QSL |
| JOHN DEERE | Models equipped with compatible Cummins engines |
Construction equipment downtime costs $800–$3,000 per day when critical components fail. A worn belt tensioner can cause serpentine belt slippage, leading to overheating, power loss, and even engine damage. Waiting 2–4 weeks for OEM parts or risking counterfeit replacements that fail in half the time only compounds these losses.
The Belt Tensioner Assembly 3936213 solves these challenges with ISO-certified quality that matches OEM specifications. As a 10-year global supplier with 20+ engineering professionals, we ensure each tensioner undergoes rigorous pre-shipment testing—just like the original equipment. Whether you’re maintaining a fleet of excavators, loaders, or generators with Cummins 6C, ISB, or QSB engines, this assembly delivers the reliability you need to keep operations running.
This tensioner assembly is critical for engines operating in high-vibration environments like construction sites, mining operations, and agricultural fields. It maintains optimal belt tension under fluctuating loads, preventing premature wear on water pumps, alternators, and other accessories. For Cummins 4B3.9 and 6B5.9 engines commonly found in heavy machinery, this part ensures consistent power transmission even during extended use.
Our 3936213 tensioner assembly features precision-machined components for exact fitment with Cummins engines. The spring-loaded design maintains constant tension across temperature extremes, while high-strength steel construction resists deformation under stress. The pulley bearing is sealed to prevent contamination, extending service life in dusty or wet conditions. Every unit is tested for torque resistance and rotational smoothness, ensuring it meets the same performance standards as OEM parts—without the premium price tag.
Cheap replacement tensioners may save money upfront, but they often fail within 6–12 months, requiring rework and additional downtime. A single unexpected breakdown can cost more than 10x the price of a quality part. Our ISO-certified assembly, backed by a 3–12 month warranty, reduces total ownership costs by minimizing failures and ensuring compatibility with your Cummins engine. It directly replaces OEM part numbers 5259022 and 3976831, eliminating the risk of mismatched components.
We partner exclusively with ISO 9001-certified factories and inspect every incoming component for material quality. Each tensioner assembly undergoes performance testing before shipment to ensure it meets OEM-equivalent specifications. With 10 years of export experience serving 120+ countries, our technical team can verify part compatibility within 2 hours, and our Guangzhou warehouse stocks 10,000+常用零件 for immediate dispatch. When you choose XUNPO, you get the expertise of a specialized工程机械配件 supplier with a proven track record in global markets.
Don’t let a faulty belt tensioner halt your operations. Send us your engine model, required quantity, and destination, and we’ll provide a competitive quotation within 24 hours. First-time clients can request sample testing to verify quality. With our ready stock and fast shipping, you can replace your tensioner and get back to work in days—not weeks.
Q: Is this an OEM part or aftermarket replacement?
A: This is an OEM-equivalent aftermarket part, manufactured by ISO-certified factories to match original specifications.
Q: How do I confirm this tensioner fits my Cummins engine?
A: Provide your engine model or serial number, and our technical team will verify compatibility within 2 hours.
Q: What warranty coverage do you offer?
A: We provide a 3–12 month warranty against manufacturing defects, with free replacement or refund for qualifying issues.
Q: What is the minimum order quantity?
A: We accept orders for 1 piece, ideal for emergency repairs or single-unit maintenance.
Q: How quickly can you ship this part?
A: In-stock items ship within 2–5 working days via your preferred shipping method (express, air, or sea).
Q: Can I request a sample before placing a bulk order?
A: Yes, first-time clients can apply for sample testing to evaluate quality and fitment.
Ready to order or need a quote?
Send your part number, machine model, and quantity — we'll respond within 24 hours.
WhatsApp: +86 13316055942 | Email: talos@xunpojx.com
Send us your requirements -- part number, machine model, quantity, and destination. Our team responds within 24 hours with a competitive quote.
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