Thermostat with Gasket & Bushing 3917324 for Cummins 4B/6B Engines – Direct Replacement

Product Specifications

Compatible Models

Frustrated by Engine Overheating and Cummins Thermostat Failures? Get the Right 3917324 Thermostat Kit for Your 4BT3.9 or 6B5.9 Engine

Every unplanned engine shutdown on a construction site costs thousands in downtime — especially when caused by a failed thermostat. Many operators waste weeks waiting for OEM Cummins parts, only to face 30–50% markup and inconsistent quality from unverified suppliers. Counterfeit or low-grade thermostat kits cause erratic temperature control, leading to coolant loss, cylinder head warping, or even catastrophic engine failure.

OEM-Equivalent Quality, Ready to Ship from Guangzhou Warehouse

This Cummins thermostat kit is manufactured in ISO 9001-certified facilities and undergoes full thermal cycling validation before shipment — ensuring stable opening at 82°C ±2°C and full flow at 90°C. With 10 years of global export experience and 10,000+ SKUs in stock, XUNPO supplies this exact kit to repair centers across North America, Southeast Asia, and the Middle East for daily maintenance on excavators, loaders, and generator sets powered by Cummins 4B/6B engines.

Where This Part Works

This thermostat replacement is engineered for high-duty-cycle environments: quarry haul trucks running 18-hour shifts, port-side container handlers operating in humid salt-air conditions, and demolition contractors using 4BT3.9-powered mini-excavators in dusty urban sites. In these applications, precise coolant regulation prevents thermal shock during rapid load changes — critical for maintaining oil viscosity and bearing life in Cummins B-series engines.

Engineering Details That Matter

The thermostat valve uses bimetallic wax-element actuation calibrated to open fully at 90°C, matching OEM thermal response curves. The gasket (3920336) is made from high-temperature nitrile rubber rated to 150°C continuous service, resisting coolant degradation and compression set over time. The bushing (3923331) features tight-tolerance machined brass with a 0.02 mm radial clearance — eliminating vibration-induced leakage at the housing interface. All three components meet SAE J1927 dimensional specs and are 100% interchangeable with original Cummins assemblies without modification.

The Real Cost of Wrong Parts

A $12 counterfeit thermostat may save $5 upfront but often fails within 200 operating hours — triggering a $2,400 engine inspection, $850 in labor, and 3 days of equipment idle time. Genuine aftermarket kits like this 3917324 thermostat kit reduce total cost of ownership (TCO) by extending service intervals to 1,200+ hours while maintaining factory-specified cooling system pressure (15 psi). Independent lab tests confirm our wax elements retain calibration accuracy after 5,000 thermal cycles — exceeding ISO 10438 durability benchmarks for heavy-duty engine thermostats.

Why Customers Trust XUNPO

Packaging & Shipping

• Individually sealed thermoformed tray with anti-static foam and printed component labels
• In-stock items ship within 2–5 working days from Guangzhou
• Flexible logistics: DHL Express (3–5 days), air freight (7–12 days), or sea freight (25–40 days)
• Real-time tracking number provided upon dispatch
• MOQ: 1 piece — designed for urgent field repairs

Get Your Cummins Thermostat Kit Now

Your engine won’t wait — and neither should your parts order. Send us “3917324 thermostat kit”, your machine model (e.g., 6BT5.9), and required quantity. You’ll receive a formal quote within 24 hours — and if it’s your first order, request a sample for testing. Every hour your equipment sits idle costs money; we keep your uptime high with reliable, traceable parts.

Frequently Asked Questions