McLeod Racing RST HD Twin - For Large Diameter Flywheel - Red Ring - 1-1/8 x 26 Spline

The McLeod 6911-07MD is the RST HD twin-disc clutch built on McLeod's large red adapter ring, so it bolts to a flywheel you already own instead of forcing you to buy a dedicated one. It is aimed at big-power street cars with a 1-1/8 in. x 26 spline input shaft: carbureted or EFI small and big blocks, Mopar and Ford builds, and anyone whose single-disc clutch now slips in third gear, chatters on takeoff or needs a leg-press to push down. McLeod rates the RST HD family for up to 950 horsepower.

What the RST HD twin-disc clutch does

A twin-disc clutch splits the clamping job between two friction discs separated by a floater plate. Doubling the friction surfaces lets McLeod hold far more torque than a single disc of the same diameter without a crushing pressure plate, which is why the RST line has a lighter-than-stock pedal. The HD version sits between the all-organic RST and the ceramic RXT: each disc carries full-face organic material on one side for smooth street engagement and segmented ceramic on the other for bite when the car is pushed hard. The red ring is the spacer that lets the pressure plate stack bolt to a large-diameter flywheel's pressure plate pattern.

Symptoms that point to a clutch upgrade

• RPM flares without a matching gain in speed during a hard pull in the upper gears (the classic slipping clutch).
• Chatter or shudder as the clutch engages from a stop, often after the old disc was overheated.
• Heavy pedal effort from a high-clamp single-disc pressure plate added to stop slipping.
• Gears that grind going into first or reverse because the clutch is not releasing fully.
• A burnt-friction smell after launches or towing.

How to confirm before buying

Rule out hydraulics first: a weak master cylinder, air in the line or a leaking slave can mimic both slipping and dragging. Check for oil on the bellhousing floor, because a rear main seal leak will glaze any new disc. Our transmission slipping diagnosis guide walks through separating clutch slip from gearbox problems, and our manual vs automatic repair cost guide helps you budget the whole job.

Fitment

This listing is the ring version only: no flywheel and no vehicle-specific year range. It is right for you if two things are true. First, your gearbox input shaft is 1-1/8 in. x 26 spline. Second, your flywheel is a large-diameter design. McLeod's red-ring list covers Chevy 168-tooth, Chrysler 143- and 172-tooth, Ford 164-, 176-, 180- and 184-tooth, and Buick, Olds and Pontiac 160- and 166-tooth flywheels. Count the ring gear teeth on the flywheel you plan to run before ordering.

Two common mistakes: late-model LS-X and Ford modular flywheels use McLeod's gold metric ring (6912 series), not this one, and small-diameter flywheels such as the Chevy 153-tooth need the black-ring McLeod 6913-07MD. If you want all-organic manners at up to 800 hp, the same red ring is used on the McLeod RST 6911-07; for track duty, see the ceramic McLeod RXT 6921-07. Not sure? Send us your engine, flywheel tooth count and transmission and we will check it.

Install notes

• Resurface the flywheel, clean the face dry, and replace a worn pilot bearing. If your flywheel uses dowel pins, they must be installed.
• Fit the disc marked bottom with its flywheel-side label forward, centered with the alignment tool.
• Bolt the ring to the flywheel with the bolts McLeod supplies, with no extra washers: 25 ft-lb for 8 mm, 35 ft-lb for 10 mm and 3/8 in.
• Line up the drive straps and alignment marks, then torque the six pressure plate nuts to 25 ft-lb and then 35 ft-lb in a star pattern, with no thread locker. Check that the diaphragm fingers sit at or below the back of the cover.
• Never add or remove balance weight on the ring; balance the flywheel only.
• Remove an old pilot bearing cleanly with a puller such as the OTC 7318 flywheel pilot bearing puller, and replace a worn release bearing matched to your gearbox.
• Break it in with normal street driving (about 1,200 shifts), not on a dyno.

Does the 6911-07MD come with a flywheel?

No. This is the adapter ring version that bolts to your existing large-diameter flywheel. McLeod sells RST HD units with dedicated steel or aluminum flywheels under other part numbers.

How do I know if I have a large-diameter flywheel?

Count the ring gear teeth. Red-ring flywheels include Chevy 168T, Chrysler 143T and 172T, Ford 164T, 176T, 180T and 184T, and Buick, Olds and Pontiac 160T and 166T. Chevy 153T, Chrysler 130T and Ford 157T are small-diameter and need the black ring.

Will this fit my LS or Coyote flywheel?

Usually not. Late-model LS-X 168T and Ford modular 164T flywheels use McLeod's gold metric ring, sold under 6912-series part numbers. Confirm before ordering.

What spline does my transmission need?

This unit uses 1-1/8 in. x 26 spline discs. Count the input shaft splines or check your gearbox specs; a 10-spline or 23-spline shaft needs a different McLeod part number.

How do I break in the RST HD?

McLeod says not to break it in on a chassis dyno. Drive normally on the street for about 1,200 clutch cycles with traction control off, then drive it hard.

What horsepower is it rated for?

McLeod rates the RST HD twin-disc line for up to 950 horsepower, above the 800 hp RST and below the RXT series.

• Transmission Slipping Diagnosis Guide
• Automatic vs. Manual Transmission Repair Cost: What to Actually Expect
• Rebuild vs Replace vs Reman Transmission