Spec 02-04 Porsche 996 3.6L Stage 4 Clutch Kit
The SPEC SP904 is a Stage 4 clutch kit for the 2002-2004 Porsche 996 Carrera with the 3.6L flat six, in both C2 and C4 form. It is the kit owners look at when the factory clutch has started to slip in third and fourth gear under full throttle, when a tuned or exhausted 3.6 is overpowering a worn disc, or when the car is due for a clutch anyway and they want more holding power without moving to a twin-disc setup. SPEC rates the SP904 at 580 ft-lb of torque capacity and lists the kit at 16 lb.
The 996 uses a single-disc dry clutch between the engine and the six-speed manual transaxle. The pressure plate bolts to the flywheel and clamps the disc against it; the hydraulic slave cylinder on the bellhousing pushes the release bearing into the diaphragm fingers to free the disc when you press the pedal. On the 2002-2004 3.6L cars Porsche used a dual-mass flywheel, and SPEC lists the SP904 for the 996 C2 and C4 specifically for use with that OE dual-mass flywheel.
What sets Stage 4 apart is the friction material. SPEC describes its Stage 4 disc as Kevlar with a steel backing, aimed at good drivability, long life and higher torque capacity than its lower stages. For comparison, the SPEC Stage 1 SP901 kit for the same cars is rated at 420 ft-lb, so the SP904 adds a large margin for modified engines while staying a single-disc, bolt-in design.
A true slip shows up as rpm rising without acceleration in a high gear at low engine speed and full load. Our slipping diagnosis guide covers the road test, and the guide to flare versus slip explains the difference between a clutch that is giving up and other drivetrain faults. Before blaming the clutch for a hard shift, check the fluid level in the shared brake and clutch reservoir and bleed the slave cylinder, since air in the line produces the same poor release. If oil is weeping from the bellhousing drain, the rear main seal or another engine seal is leaking and has to be fixed during the clutch job or it will contaminate the new disc.
This listing is for the 2002-2004 Porsche 996 3.6L, C2 and C4, with the factory dual-mass flywheel. SPEC also lists the SP904 for the 2000-2004 Boxster S and, with a billet single-mass flywheel, for the 2009-2012 997.2 Base, S and GTS. The 1999-2001 996 with the 3.4L and the 996 Turbo and GT models use different clutch parts, so this kit is not for those cars. If you plan to fit a single-mass flywheel such as the SPEC SP90A aluminum flywheel on a 2002-2004 car, send us the year and VIN first so we can confirm the matching clutch, because SPEC lists the SP904 for the 996 with the dual-mass unit. You can also browse the full clutch and rebuild kit range.
| Brand | SPEC |
| Part number | SP904 |
| Fits | Spec 02-04 Porsche 996 3.6L Stage 4 Clutch Kit |
| Vehicle fitment | Porsche 996 (2002-2004) |
| Type | Clutch Kits - Single |
| Condition | New |
| Ships | Same business day (in stock), from the USA |
| Warranty | 1-year |
No. SPEC lists the SP904 for the 2002-2004 996 C2 and C4 with the 3.6L engine. The earlier 3.4L cars and the 996 Turbo and GT models use different clutch parts. Send us your year and VIN if you are unsure which engine your car has.
Only if it passes inspection. SPEC lists this kit for the 996 with the OE dual-mass flywheel, but a dual-mass unit cannot be resurfaced. If the two halves have excessive play, it rattles at idle, or the friction face is cracked or heat-marked, replace it at the same time.
SPEC rates the SP904 at 580 ft-lb of torque capacity, compared with 420 ft-lb for the SPEC Stage 1 SP901 kit for the same cars.
SPEC describes its Stage 4 disc as Kevlar with a steel backing, intended for good drivability, long life and higher torque capacity than its lower stages.
The 996 clutch shares the brake fluid reservoir, so use fresh brake fluid of the grade Porsche lists for your car and bleed both the clutch slave and the brakes if the fluid is old.
Expect firmer engagement than a worn stock clutch. If your car is daily driven and mostly stock, the Stage 1 SP901 may suit you better; the SP904 is the better match for tuned 3.6L engines or regular track use.
