Replacement Soft Seat Thermostat for Cummins ® B/ISB/QSB Applications 4B/6B OEM Cross References: 3972071 Superseded/Alternate Numbers: M-3917324

Product Details

Thermostat – Soft Seat | Cummins Engine | M-3972071

Thermostat – Soft Seat is an OEM-quality component designed for the Cummins diesel engine. Manufactured to meet or exceed original specifications, this part ensures reliable performance and long service life. OE reference: M-3972071.

Each product from HeavyDutyKits.com is backed by our commitment to quality and compatibility, helping mechanics and fleet operators maintain top efficiency.

Features:

• Direct-fit replacement for Cummins OE M-3972071
• Engineered for durability under high-load diesel conditions
• Ideal for rebuilds, maintenance, or performance upgrades

Order today from HeavyDutyKits.com ? your trusted source for heavy-duty diesel engine parts.

Application & Fitment

• Engine Make: Cummins
• Engine Model / Application: B/ISB/QSB

Confirm the original part number and engine identification before ordering. Where applicable, also verify serial-number range, production year, piston style, bearing size or other configuration notes shown in the product information.

Part Numbers & Cross References

• OEM Cross Reference: 3972071
• Alternate / Superseded: M-3917324
• Interstate-McBee Reference: M-3972071

Need Help Confirming Fitment?

Use the engine model, serial number and original part number when checking compatibility. For kits and sets, review the complete component breakdown above before ordering because contents can vary by engine configuration.