Clutch Masters 05-06 Chevrolet Corvette 6.0L LS2 850 Series Twin Disc Clutch Kit

The 2005 and 2006 C6 Corvette with the 6.0L LS2 and the six-speed manual makes 400 hp and 400 lb-ft from the factory, and once it gets a cam, a blower or nitrous the stock clutch starts to slide. Clutch Masters 04216-TD8R-SH is an FX850 twin disc in the Race stage for that car, supplied with a steel flywheel and a hydraulic release bearing. If your C6 slips on a big pull, smells hot after a track session, or you are adding power and want the clutch done once, this kit is built for it.

What the FX850 twin disc does in a C6 Corvette

The FX850 is an 8.5 inch (216 mm) twin disc that makes its holding power with two friction discs and a stronger clamp instead of a large diameter. In the Race stage (TD8R) a sprung ceramic disc is connected directly to a second ceramic disc, so both share the load while the sprung hub cushions driveline shock. Clutch Masters machines the cover from billet aluminum with a Type 3 hard anodize and says it flexes about one tenth as much as a cast or stamped cover, so the pedal releases at the same point lap after lap. The QR quick-release pressure plate uses three spring-loaded bolts to help the plate lift evenly and reduce internal chatter. The steel flywheel is a 1045 billet part with a black oxide finish.

Symptoms that point to an overmatched clutch

• RPM rises in third or fourth at wide open throttle while the car does not pull harder
• Slip that gets worse late in a track session or a long highway pull
• Burnt friction smell after launches
• Shudder pulling away from a glazed disc or heat-spotted flywheel
• Slip that appeared after a supercharger, nitrous or a big cam

How to confirm before you buy

A slip test in a high gear at low rpm, going to full throttle and watching for rpm that outruns road speed, confirms a slipping clutch. Before you blame the disc, look at the hydraulics: a leaking release bearing or air in the line can keep the clutch from clamping fully, and a pedal that sticks or sinks points that way. Also think about how the car is driven. Clutch Masters says driving style and purpose should decide the clutch before power does, and a Race-stage ceramic twin disc is stiffer and grabbier than stock. If your C6 is mostly a street car with modest mods, a street twin such as the ACT Mod-Twin 10.5 street kit may suit it better. Our manual versus automatic repair cost guide covers what the labor runs.

Fitment

The listing is for the 2005-2006 Chevrolet Corvette with the 6.0L LS2 and the six-speed manual. The LS2 ran in the C6 from 2005 through 2007, and those cars used the T-56 manual until the TR6060 replaced it for 2008. Clutch Masters' own catalog groups the 04216 base number with later C6 LS2, LS3 and LS7 manual cars as well, but this listing is for 2005-2006, so if you have a 2007 or later car, a Z06, or any swapped parts, send us the year and VIN before you order. It does not fit the automatic. Other drivetrain parts are in our rebuild kits department.

Install notes

• Clutch access on a Corvette is a big labor job, so check the rear main seal and the release bearing line fittings while you are in there.
• Bolt on the supplied steel flywheel with new bolts to the specified torque, and use only this flywheel with the pressure plate.
• Assemble the discs and floater in the order in the instructions, center them with an alignment tool such as our 18-piece clutch alignment kit, and tighten the cover evenly in a crisscross pattern.
• Set up the hydraulic release bearing per the instructions and bleed the system with the fluid GM lists on the reservoir; a pneumatic fluid extractor and bleeder speeds that up.
• Expect a heavier pedal; Clutch Masters puts the FX850 at about 50 percent more pedal pressure on average. Break it in for 500 miles with no full-throttle shifts.

Does this fit a 2007 Corvette or a Z06?

This listing is for the 2005-2006 LS2 manual car. Clutch Masters groups the 04216 number with later C6 manual cars too, but send us the year and VIN for a 2007, an LS3 car or a Z06 and we will confirm before it ships.

What is included?

The FX850 twin disc clutch with Race-stage ceramic discs, a steel flywheel and a hydraulic release bearing.

Is the Race stage too aggressive for the street?

It is a ceramic twin disc with a firmer pedal and quicker bite than stock. It can be driven on the street, but if the car rarely sees the track, a street-stage twin disc will be more comfortable.

Will the pedal be heavier?

Yes. Clutch Masters says FX850 twin discs average about a 50 percent increase in pedal pressure depending on the application.

Does it work with an automatic C6?

No. It is only for six-speed manual cars.

How do I break it in?

Drive at least 500 miles of normal stop-and-go driving with no full-throttle shifting or compression braking before using full power.

• Automatic vs. Manual Transmission Repair Cost: What to Actually Expect