South Bend Clutch 1670507-6 G56 Replacement Flywheel
Solid-mass steel flywheel for 2005.5–2018 Dodge Ram 5.9L / 6.7L Cummins with G56 6-speed

This is a replacement solid flywheel for trucks that already run a South Bend single-disc G56 clutch — not a drop-in for the factory dual-mass clutch.

Factory dual-mass flywheels on G56 Cummins trucks are built for quiet stock duty. Once you add a South Bend single-disc clutch and start towing, hauling, or making more power, that OEM unit becomes a weak point: heat, warpage, slop, and inconsistent engagement. The 1670507-6 replaces it with a CNC-machined, single-mass steel flywheel designed for higher plate loads and longer service life.

South Bend machines these from low-carbon, hot-rolled steel. The result is a flywheel that runs cooler, resists warping better than stock, and stays in balance so engagement stays smooth instead of grabbing or chattering. It is built in the USA and intended to exceed OE specs for trucks that work.

Important compatibility note
This flywheel is for use with South Bend G56 single-disc kits (including G56-OK, G56-OFEK, and G56-OK-HD). It is not a replacement for a stock clutch or dual-disc setup. Confirm your current clutch before ordering.

Key benefits

• Solid single-mass design replaces the factory dual-mass flywheel
• Low-carbon, hot-rolled steel for higher plate-load capacity and warp resistance
• CNC machining for tight tolerances and correct balance
• Lower operating temperatures under load
• Smoother, more consistent clutch engagement
• Built for towing, daily driving, and performance Cummins applications
• Made in the USA

Fitment

Fits 2005.5–2018 Dodge / Ram 2500, 3500, and 4500 trucks with the 5.9L or 6.7L Cummins and G56 6-speed manual transmission, provided a South Bend single-disc clutch is already installed. Year coverage varies slightly by retailer listing (most commonly 2005.5–2017/2018). Verify your year, engine, and current clutch kit before purchase.

Specs

Part number 1670507-6. Solid / single-mass steel flywheel made from low-carbon, hot-rolled steel for G56 single-disc conversion or replacement. 1-piece rear main seal style. Friction surface is not replaceable. Made in the USA for performance and heavy-duty use.

Who this is for

Cummins owners who already converted the G56 to a South Bend single-disc clutch and now need a fresh flywheel surface — whether the old one is heat-checked, worn, or being replaced during a clutch service. It is the right part for a working truck that needs a stronger, more predictable setup than the factory dual-mass unit.

Not for: stock clutch replacements, dual-disc South Bend setups, or trucks still running the OEM dual-mass flywheel.