GC Aftermarket Cummins C5.9 Graphite Exhaust Mixer Gasket | Sawley's Select Marine Parts

🔧 Product Description

Aftermarket Cummins C5.9 Graphite Exhaust Mixer Gasket - Part Number: GC

A heavy graphite-and-copper exhaust gasket for Cummins marine turbocharger and mixing-elbow joints. It is an upgraded sealing option for the Cummins 3921961 gasket position where a compressible graphite seal is preferred.

⚙️ Key Features

• Graphite sealing core with copper reinforcement

• Designed for high-temperature marine diesel exhaust service

• Conforms to minor flange irregularities

• Used in the HDI C5.9 and CUMA exhaust systems

• Replace whenever the flange joint is separated

🔄 Supersession & Cross Reference

OEM Supersession Chain:

• HDI GC → Alternative sealing design for Cummins 3921961 gasket position

OEM / Related Numbers:

• HDI GC

• Cummins 3921961

Aftermarket / Verified Equivalents:

• HDI Marine: GC

🚤 Compatibility

Commonly used on:

• Cummins marine turbocharger and mixing-elbow joints

Typically suits:

• Engine models:

• Cummins 6BT5.9

• Cummins 4BTA

• Cummins 6BTA5.9

• Cummins QSB5.9

• Cummins 6CTA8.3

• Cummins QSC8.3

• Cummins QSB6.7

• Cummins QSB6.9

• Cummins QSL9

• Material: graphite with copper reinforcement

• Joint Type: turbocharger / exhaust-mixer flange

🔌 Function

The gasket seals the hot exhaust flange while accommodating heat-cycle movement between the turbocharger and marine exhaust hardware.

Common signs of failure:

• Black soot tracking around the joint

• Cooling-water seepage or salt deposits at the flange

• Exhaust smell or fumes in the engine compartment

• Burnt, split, crushed or hardened sealing material

• Corrosion or erosion of the mating faces

📦 Condition

• Brand new aftermarket replacement part

• New and unused

• Supplied in manufacturer or equivalent protective packaging