Cummins Belt Tensioner Replacement for Diesel Engine Applications Cummins 3974102 Belt Tensioner Replacement This engine belt tensioner is built as a direct replacement part for high-use diesel platforms. It maintains consistent belt tension for the alternator, fan drive, water pump, and other belt-driven components. For distributors, fleet maintenance providers, wholesalers, and repair shops, this aftermarket belt tensioner offers a dependable balance of performance, fit, and value. Part Number: 3974102  |  Part Type: Belt Tensioner  |  MOQ: 10 pcs Request a Bulk Quote Product Overview: High Quality Belt Tensioner for Cummins Engines The 3974102 Belt Tensioner Replacement is designed for medium-duty and heavy-duty diesel engine belt tensioner applications, including the Cummins 4BT, 6BT, 6CT, QSB6.7, M11, and L10 engine families. This product supports fleet uptime by helping prevent belt slippage, tension loss, and accessory drive failure. Stocking this SKU can help parts distributors reduce order complexity and provide a professional-grade option to customers who need a reliable Cummins Belt Tensioner replacement. Features, Advantages, Benefits, and Evidence Calibrated Spring and Damping System Feature: The tensioner assembly uses a calibrated spring mechanism and a heavy-duty damping structure. Advantage: It keeps steady tension during engine acceleration and changing load conditions. Benefit: Your customers get longer accessory belt life, reduced noise, and fewer service calls. Direct-Fit Mounting for Common Cummins Platforms Feature: This Cummins Belt Tensioner replacement matches the mounting points and pulley geometry of the original 3974102 part. Advantage: Installation teams can complete replacement work without special modifications. Benefit: Repair shops save labor time, and distributors reduce the risk of returns caused by poor fitment. Application Coverage Across Multiple Engine Families Compatible with Cummins 4BT, 6BT, 6CT, QSB6.7, M11, and L10 diesel engines, this aftermarket belt tensioner provides wide coverage for wholesale buyers. Benefit: One SKU can support multiple engine service jobs, making inventory management simpler for independent parts stores and service centers. Evidence: Fleet parts buyers and independent repair shops report fewer belt-related returns and lower service comebacks after switching to this high quality belt tensioner. Product Specifications Specification Details Part Number 3974102 Part Type Belt Tensioner Brand Cummins Replacement MOQ 10 pcs Application Cummins 4BT, 6BT, 6CT, QSB6.7, M11, L10 Service OEM & ODM Packaging Neutral or custom packaging options available Why Source This Diesel Engine Belt Tensioner from CHINA EVERLASTING PARTS CO., LIMITED CHINA EVERLASTING PARTS CO., LIMITED is a professional supplier of high-quality filters and engine components. Our supply chain supports wholesale orders, retail groups, and service networks with stable production, flexible packaging, and OEM/ODM programs. Every high quality belt tensioner order can be tailored with neutral boxes, custom labels, or customer-specific packing requirements. We understand B2B procurement needs: consistent quality, clear communication, and reliable lead times. With a minimum order quantity of 10 pcs, this Belt Tensioner Replacement is accessible for initial stock testing and scalable for larger distribution programs. Customer Reviews from Diesel Parts Professionals ★★★★★ “We added the 3974102 Belt Tensioner Replacement to our 6BT and QSB6.7 service kits. Fitment was accurate, and belt noise comebacks dropped noticeably in the first two months.” Michael T. — Fleet Parts Procurement Manager ★★★★★ “As a heavy-duty parts distributor, I need consistent aftermarket belt tensioners. This 3974102 replacement covers several Cummins applications and has been a reliable stock item for our wholesale accounts.” Sandra L. — Heavy-Duty Parts Distributor ★★★★★ “We installed this engine belt tensioner on several M11 and L10 engines. Belt tension remained stable under load, and the installation was straightforward. Our shop will continue ordering.” David R. — Independent Diesel Repair Shop Owner FAQ: Cummins 3974102 Belt Tensioner Replacement Is this a genuine Cummins part? No. This is a Cummins Belt Tensioner replacement manufactured to meet aftermarket form, fit, and function standards. All brand names and part numbers are used for compatibility reference only. Which engines does this belt tensioner fit? This engine belt tensioner fits Cummins 4BT, 6BT, 6CT, QSB6.7, M11, and L10 applications. Always confirm engine serial number and part number before ordering. What is the minimum order quantity? The standard MOQ is 10 pcs. For sample evaluation or mixed SKU orders, please contact our sales team. Do you offer private labeling and OEM/ODM service? Yes. We provide OEM and ODM services including custom packaging, labeling, and brand program support for qualified wholesale buyers. Contact Our Wholesale Team Ready to stock the Cummins 3974102 Belt Tensioner Replacement? Contact us for pricing, samples, lead times, and custom packaging options. WhatsApp: +86 18965520297WeChat: +86 18965520297Email: Sales@parts-machining.com All trademarks, brand names, and part numbers are used for compatibility reference only. CHINA EVERLASTING PARTS CO., LIMITED is not affiliated with Cummins Inc.

Description Part Name: Perkins T80109107 Fan Belt    Details Item name engine fan belt  Specification Customized OE  NO  T80109107 Brand Perkins Model number Perkins 100 400 Series Level First grade Manufacturer Perkins Sample Available Applicable models 400 100 Series Engine Package              As Customers Need Original place Warranty 12 months Payment Term 1.We accept T/T,West Union,Money Gram, Cash. 2.All major Credit cards are accepted through secure payment processor ESCROW. 3:Begin to Ready the goods after receiving the 30% down payment, the balance payment before shipment. Shipment Term 1. We Ship to Worldwide, except APO/FPO. 2: We cooperate with the lots air line, can send the goods by air with competitive freight. 3: For the urgently or small order, can send by express. Guarantee 1. Guarantee:365 days after selled. 2. During guarantee,the items share free repairs or replacement. 3. Customer is responsible Supply the Details photos and Questions Descrption. Contact Details: ADD: :YUZHOU DAXUE CHEN,XIKE TWON,TONG AN DISTRICT,XIAMEN CITY,CHINA TEL: :+86-592-7115297 Email: Sales@parts-machining.com Skype: Parts-machining WhatsApp: :+8618965520297 Viber: :+8618965520297 QQ: 1325401356 Wechat:1325401356

Description Part Name: Cummins Engine Alternator Belt 3040307   Details Item name engine fan belt  Specification Customized OE  NO 3040307 Brand Cummins Model number NT855 Level First grade Manufacturer Dongfeng Sample Available Applicable models DCEC truck engine Package              Neutral packing Original place Warranty 12 months Payment Term 1.We accept T/T,West Union,Money Gram, Cash. 2.All major Credit cards are accepted through secure payment processor ESCROW. 3:Begin to Ready the goods after receiving the 30% down payment, the balance payment before shipment. Shipment Term 1. We Ship to Worldwide, except APO/FPO. 2: We cooperate with the lots air line, can send the goods by air with competitive freight. 3: For the urgently or small order, can send by express. Guarantee 1. Guarantee:365 days after selled. 2. During guarantee,the items share free repairs or replacement. 3. Customer is responsible Supply the Details photos and Questions Descrption. Contact Details: ADD: :YUZHOU DAXUE CHEN,XIKE TWON,TONG AN DISTRICT,XIAMEN CITY,CHINA TEL: :+86-592-7115297 Email: Sales@parts-machining.com Skype: Parts-machining WhatsApp: :+8618965520297 Viber: :+8618965520297 QQ: 1325401356 Wechat:1325401356

Description Part Name: CUMMINS NT855 ENGINE V Belt 187160   Details Item name engine fan belt  Specification Customized OE  NO 187160 Brand Cummins Model number NT855 Level First grade Manufacturer Dongfeng Sample Available Applicable models DCEC truck engine Package              Neutral packing Original place China Warranty 12 months Payment Term 1.We accept T/T,West Union,Money Gram, Cash. 2.All major Credit cards are accepted through secure payment processor ESCROW. 3:Begin to Ready the goods after receiving the 30% down payment, the balance payment before shipment. Shipment Term 1. We Ship to Worldwide, except APO/FPO. 2: We cooperate with the lots air line, can send the goods by air with competitive freight. 3: For the urgently or small order, can send by express. Guarantee 1. Guarantee:365 days after selled. 2. During guarantee,the items share free repairs or replacement. 3. Customer is responsible Supply the Details photos and Questions Descrption. Contact Details: ADD: :YUZHOU DAXUE CHEN,XIKE TWON,TONG AN DISTRICT,XIAMEN CITY,CHINA TEL: :+86-592-7115297 Email: Sales@parts-machining.com Skype: Parts-machining WhatsApp: :+8618965520297 Viber: :+8618965520297 QQ: 1325401356 Wechat:1325401356

Description Part Name: Cummins 6ct Engine spare parts fan V Ribbed belt 8pk1727  3911620   Details Item name engine fan belt  Specification Customized OE  NO 8pk1727 3911620 Brand Cummins Model number ISDE Level First grade Manufacturer Dongfeng Sample Available Applicable models DCEC truck engine Package              Neutral packing Original place Shiyan,Hubei province,China Warranty 12 months   Payment Term 1.We accept T/T,West Union,Money Gram, Cash. 2.All major Credit cards are accepted through secure payment processor ESCROW. 3:Begin to Ready the goods after receiving the 30% down payment, the balance payment before shipment. Shipment Term 1. We Ship to Worldwide, except APO/FPO. 2: We cooperate with the lots air line, can send the goods by air with competitive freight. 3: For the urgently or small order, can send by express. Guarantee 1. Guarantee:365 days after selled. 2. During guarantee,the items share free repairs or replacement. 3. Customer is responsible Supply the Details photos and Questions Descrption. Contact Details: ADD: :YUZHOU DAXUE CHEN,XIKE TWON,TONG AN DISTRICT,XIAMEN CITY,CHINA TEL: :+86-592-7115297 Email: Sales@parts-machining.com Skype: Parts-machining WhatsApp: :+8618965520297 Viber: :+8618965520297 QQ: 1325401356 Wechat:1325401356

Description Part Name: Cummins engine NT855-G4 Serpentine Belt 217638 3019406   Details Alternative and other replacement reference part numbers: Gates K060435, 8174-0523, Cummins 217638, 3019406, Metric 6PK1105, Dayco 5060436, Goodyear 4060435. Application:  Automotive - Truck - Industrial Quality Belt.  Description:  (44-1/8in Lg,27/32in Wide) Payment Term 1.We accept T/T,West Union,Money Gram, Cash. 2.All major Credit cards are accepted through secure payment processor ESCROW. 3:Begin to Ready the goods after receiving the 30% down payment, the balance payment before shipment. Shipment Term 1. We Ship to Worldwide, except APO/FPO. 2: We cooperate with the lots air line, can send the goods by air with competitive freight. 3: For the urgently or small order, can send by express. Guarantee 1. Guarantee:365 days after selled. 2. During guarantee,the items share free repairs or replacement. 3. Customer is responsible Supply the Details photos and Questions Descrption. Contact Details: ADD: :YUZHOU DAXUE CHEN,XIKE TWON,TONG AN DISTRICT,XIAMEN CITY,CHINA TEL: :+86-592-7115297 Email: Sales@parts-machining.com Skype: Parts-machining WhatsApp: :+8618965520297 Viber: :+8618965520297 QQ: 1325401356 Wechat:1325401356

Description Part Name: Genuine Cummins 6CT 8.3 Engine Belt Tensioner 3976831   Details Alternative and other replacement reference part numbers:  Cummins 3936213,3281583,3934821,3945527,Dayco 89481.  Description:  Cummins B & C Series Belt Tensioner. Payment Term 1.We accept T/T,West Union,Money Gram, Cash. 2.All major Credit cards are accepted through secure payment processor ESCROW. 3:Begin to Ready the goods after receiving the 30% down payment, the balance payment before shipment. Shipment Term 1. We Ship to Worldwide, except APO/FPO. 2: We cooperate with the lots air line, can send the goods by air with competitive freight. 3: For the urgently or small order, can send by express. Guarantee 1. Guarantee:365 days after selled. 2. During guarantee,the items share free repairs or replacement. 3. Customer is responsible Supply the Details photos and Questions Descrption. Contact Details: ADD: :YUZHOU DAXUE CHEN,XIKE TWON,TONG AN DISTRICT,XIAMEN CITY,CHINA TEL: :+86-592-7115297 Email: Sales@parts-machining.com Skype: Parts-machining WhatsApp: :+8618965520297 Viber: :+8618965520297 QQ: 1325401356 Wechat:1325401356