McLeod RXT Twin Disc Clutch Kit 14-17 Chevrolet SS Sedan 6.2L (26 Spline)

The Chevrolet SS sedan only got a manual transmission for its last few model years, and owners who add a supercharger, cam or nitrous to the 6.2L LS3 quickly find the stock single disc clutch is the weak link. The McLeod 6406607M is an RXT street twin disc kit built specifically for the manual SS, with its own billet steel flywheel, so it goes in as one matched package instead of a pile of parts from different catalogs.

What the RXT twin does in a Chevrolet SS

A twin disc clutch splits the job across two friction discs with a floater plate between them. Doubling the friction surface lets McLeod hold far more torque than a single disc of the same diameter, while the pressure plate can stay soft enough for daily driving. McLeod's own product copy rates the standard RXT street twin at roughly 1000 horsepower and describes the pedal as lighter than stock, which matters in a 3,900 pound sedan that still gets driven in traffic.

This version is the modular assembly: pressure plate, two ceramic lined discs on a sprung hub, a floater plate, an adapter ring and a steel flywheel machined for the LS3 6-bolt crank and its 168 tooth ring gear. The input spline is 1-1/8 inch by 26, the size used by the Tremec six-speed in the SS. Ceramic facings bite hard and take heat well, and the sprung hub takes some of the shock out of engagement so the driveline is not hit as hard on a launch. Steel was chosen over aluminum here because the extra mass makes pulling away from a stop smoother in a heavy car.

Symptoms that point to this upgrade

• RPM climbs without the car pulling harder during a wide open shift, worst in third and fourth
• Slip that shows up only after the clutch is hot from a few hard pulls or a track session
• Chatter or shudder on takeoff from a glazed disc or a heat spotted flywheel
• A burnt friction smell after a launch or a highway pass
• A power target with boost or nitrous that is beyond what the factory clutch was built to hold

How to confirm the clutch is the problem

Do a slip test in a high gear at low rpm: roll into full throttle and watch the tach. If engine speed rises faster than road speed, the clutch is slipping. Before you blame the friction, check the release side. Air in the hydraulic line or a leaking concentric slave can hold the clutch partly released and cook a good disc in a few miles. Look for fluid at the bellhousing seam and a pedal that sinks or changes height. Our manual versus automatic repair cost guide helps you budget the whole job, since labor to drop the transmission is the same whether you buy a stock clutch or this one.

Fitment

Our listing title reads 2014 to 2017, but the 2014 Chevrolet SS was sold with the six-speed automatic only. The manual became available for the 2015 model year, and McLeod's own description of this kit lists the 2015 to 2017 SS sedan with the LS3 6.2L, 168 tooth ring gear and 1-1/8 x 26 spline input. If your SS is a factory manual car, this is the kit. If yours is an automatic car converted to a manual, confirm crank flange, ring gear count and input spline before ordering, or send us the year and VIN and we will check it. Prefer to keep a flywheel you already have? The RXT 1200 twin assembly for 6-bolt LS cranks and the softer RST organic twin assembly are built for the same crank pattern. More options are in our rebuild kits department.

Install notes

• The kit contents we checked list the pressure plate, two ceramic discs, steel flywheel, floater plate, adapter ring and pilot tool. A release bearing and pilot bearing are not listed, so plan for them. McLeod's twin disc instructions recommend replacing a factory hydraulic slave at clutch time.
• Pull the old pilot bearing with a pilot bushing remover and install a fresh one so the input shaft is supported.
• Stack the discs in the marked order with the bottom disc's flywheel side facing the flywheel. Keep the alignment marks on the adapter ring and pressure plate lined up, and center everything with the supplied pilot tool before tightening.
• McLeod calls for running the pressure plate nuts to 25 ft-lb and then 35 ft-lb in a star pattern, with no thread locker on the studs, and using the supplied adapter ring bolts without washers.
• Bleed the hydraulics fully and break the clutch in with about 1200 normal street engagements, never on a chassis dyno.

Will this fit a 2014 Chevrolet SS?

Not as a bolt-in for a factory car. The 2014 SS was automatic only, and the manual arrived for 2015. McLeod lists this kit for the 2015 to 2017 manual SS. Converted cars need the crank, ring gear and spline checked first.

Does the kit include a flywheel?

Yes. It comes with a billet steel flywheel for the LS3 6-bolt crank with a 168 tooth ring gear, plus the pressure plate, two ceramic discs, floater plate, adapter ring and pilot tool.

Is a throwout bearing included?

The kit contents we checked do not list a release bearing or pilot bearing. Budget for a new slave or release bearing and a pilot bearing while the transmission is out.

How much power will the RXT handle?

McLeod describes the standard RXT street twin as able to handle about 1000 horsepower while staying streetable. If you plan more than that, look at their RXT 1200 versions.

Is it hard to drive on the street?

McLeod rates the pedal as lighter than stock, and the sprung hub and steel flywheel help it pull away smoothly. Ceramic discs do engage more quickly than an organic disc, so expect a short learning curve.

How do I break in the new clutch?

McLeod says to drive normally on the street for about 1200 clutch engagements with traction control off, shifting up and down through the gears, and not to break it in on a chassis dyno.

• Automatic vs Manual Transmission Repair Cost