McLeod RST Twin GM LSA/LT4 1-1/8 x 26 Spline w/ 168T 8-Bolt Aluminum Flywheel

A supercharged LSA or LT4 with a pulley swap and a tune will overpower the factory clutch in a CTS-V or Camaro ZL1 quickly. Slipping on the 2-3 shift, a fading engagement point and a hot clutch smell after a pull are the usual warnings. McLeod part number 6306807 is the RST organic twin disc clutch on a billet aluminum 8-bolt flywheel with a 168 tooth ring gear and a 1-1/8 in. x 26 spline, built for the GM manual cars on McLeod's application list.

What the RST twin clutch does behind an LSA or LT4

Two organic discs with a floater between them double the friction area, so the clutch can hold far more torque without the stiff pedal of a heavy single disc pressure plate. McLeod rates the RST at about 800 horsepower and positions it as a street clutch: organic facings, smooth engagement, a pedal lighter than stock, and not intended for competition. For a daily-driven CTS-V or ZL1 with moderate power adders it is the easiest twin to live with. Cars headed for drag radials and repeated launches are better served by the ceramic RXT version, 6306807M.

The factory cars use a dual mass flywheel. This kit replaces it with a dedicated aluminum flywheel, which cuts rotating weight. The engine revs faster, and you will hear more gear rattle at idle.

Symptoms on these cars

• Clutch slip at high rpm in second or third gear after a pulley or tune upgrade.
• Burnt friction smell and a pedal that grabs at a different point when hot.
• Chatter pulling away, often from oil on the disc from a rear main or input seal leak.
• Difficult shifts or grinding when the clutch or the concentric slave is not releasing fully.

How to confirm the clutch is at fault

Bleed the system and check the slave before condemning the clutch. A failing concentric slave can leak into the bellhousing and cause both poor release and contaminated discs. For slip, a fourth gear pull from low rpm shows rpm rising faster than road speed. Our slipping diagnosis guide covers the test. If you are deciding whether the gearbox itself also needs work, read rebuild vs replace vs reman.

Fitment

McLeod's application line for 6306807 lists 2009-2015 Cadillac CTS-V, 2012-2024 Camaro ZL1 and 2016-2024 Camaro with the LT1 V8, all with the manual transmission. Spec: 8-bolt crank, 168 tooth ring gear, 1-1/8 in. x 26 spline, aluminum flywheel. The fifth-generation ZL1 (2012-2015) uses the supercharged LSA, the sixth-generation ZL1 uses the LT4, and the sixth-generation SS uses the LT1 with the TR-6060 manual. Automatic cars do not apply, and the earlier LS3 6-bolt Camaro SS needs a different part number. If your car has been modified or you are unsure, count the crank bolts or send us your year and VIN before ordering.

Install notes

• Inspect the ring gear and pilot bearing. Replace a rough pilot bearing with help from a pilot bushing remover.
• On 2016-up Camaros, the concentric slave and bearing is a sensible replacement while the gearbox is out. We carry a 2016-2021 Camaro slave cylinder bearing.
• Bottom disc first, flywheel side forward. Line up the adapter ring and pressure plate marks and keep the drive straps stacked.
• Pressure plate nuts in a star pattern to 25 ft-lb, then 35 ft-lb. No thread locker, and no washers beyond what McLeod supplied.
• If balancing the assembly, add or remove weight on the flywheel only, never on the adapter ring.
• Bleed with the brake fluid type on the reservoir cap, then break in over about 1,200 street shifts with traction control off.

Need more holding power on the same car? The RXT HD with steel flywheel, 6406807HD is built for bigger power.

Does McLeod 6306807 fit a 2014 Camaro SS?

No. Fifth-generation Camaro SS manual cars use the LS3 with a 6-bolt crank. This kit is for the 8-bolt LSA and LT engines on McLeod's list: 2009-2015 CTS-V, 2012-2024 ZL1 and 2016-2024 LT1 Camaro manuals.

How much power can the RST handle?

McLeod rates the RST organic twin at about 800 hp for street use. For harder use, look at the RXT 6306807M or the RXT HD 6406807HD.

Do I need to replace the slave cylinder?

It is not required, but the concentric slave lives inside the bellhousing, so replacing a worn or leaking one while the transmission is out saves doing the job twice.

Will it work with my factory dual mass flywheel?

No flywheel reuse is needed. This part number includes its own 8-bolt aluminum flywheel with a 168 tooth ring gear that replaces the dual mass unit.

How do I break in the clutch?

About 1,200 normal shifts on the street with traction control off before any hard launches. McLeod says not to break it in on a chassis dyno.

• Transmission Slipping Diagnosis Guide
• Rebuild vs Replace vs Reman Transmission
• Automatic vs Manual Transmission Repair Cost