McLeod 2024 Ford Mustang RST 1 X 23 Spline with 8 Bolt AL Flywheel

Building a 2024-and-later S650 Mustang with a six-speed manual and adding a supercharger, turbo kit or nitrous? The factory single-disc clutch is usually the first thing to give up. McLeod part number 6339825 is the RST twin disc clutch with an 8-bolt billet aluminum flywheel for the new Coyote 5.0L cars, built with a 1 inch, 23-spline disc hub. It is the street-focused entry point of McLeod's twin disc range for this car.

What the RST twin disc does in an S650 Mustang

Instead of one large disc, the RST uses two organic-faced discs with a floater plate between them. Doubling the friction surface lets the clutch hold far more torque without a heavier pedal - McLeod says the RST handles about 800 horsepower while giving a lighter-than-stock pedal feel and clean release. Organic facings engage smoothly, so the car stays easy to drive in traffic. The billet aluminum flywheel lowers rotating mass for quicker revs between shifts.

McLeod builds three versions on the same 1x23 spline and 8-bolt pattern. The RST here is for high-power street cars and is not meant for competition. The RXT 6339825M switches to ceramic discs and is rated around 1,100 horsepower, and the RXT HD 6339825HD adds more clamp load for the biggest builds. Pick the RST if the car still spends most of its time on the street.

Symptoms that point to a clutch upgrade

• Clutch slipping under load once boost or nitrous comes in, especially in third through fifth
• Rpm flare on fast shifts at the drag strip
• Chatter on takeoff from a glazed factory disc
• Noise when the pedal is pressed from a tired release bearing
• Hard to engage gears if the clutch no longer releases fully

How to confirm before you buy

A warm-engine pull in a high gear is the clean test: if rpm rises while speed does not, the clutch is slipping. Data logs that show engine speed and wheel speed drifting apart confirm it. Rule out a leaking hydraulic slave cylinder and any rear main seal leak first, since both will ruin new discs. Our slipping diagnosis guide explains how to separate clutch slip from other faults, and the rebuild vs replace guide helps if the gearbox also needs attention.

Fitment

The listing is catalogued for the 2024 Ford Mustang 5.0L six-speed manual, and McLeod's own description names the 2024-2026 Dark Horse 5.0L with the 8-bolt crank and 1x23 spline. Ford fits the S650 GT with a Getrag MT82-D4 and the Dark Horse with a Tremec TR-3160, so do not assume both share an input spline. Before ordering, confirm your trim and that the old disc hub is 1 inch, 23-spline, or send us your VIN and we will check it. It does not fit the 10-speed automatic, the EcoBoost or the Dark Horse SC dual-clutch. More options are on our hard parts page.

Install notes

• Fit the bottom disc with its "flywheel side" label toward the flywheel and center it with the supplied tool.
• Line up the alignment marks on the adapter ring and pressure plate and keep the drive straps stacked in the same opening.
• No thread locker on the pressure plate studs; torque the nuts to 25 ft-lb, then 35 ft-lb, in a star pattern.
• Check the pilot bearing and replace it if it is rough - a Lisle pilot bushing remover pulls it without damaging the crank.
• Resurfacing is not needed with the new flywheel, but every friction face must be clean and dry.
• Break-in is about 1,200 normal clutch cycles on the street with traction control off; never break it in on a chassis dyno.

Does this fit the 2024 Mustang GT or only the Dark Horse?

The listing is catalogued for the 2024 Mustang 5.0L manual, and McLeod's description names the 2024-2026 Dark Horse. The GT uses a Getrag MT82-D4 and the Dark Horse a Tremec TR-3160, so confirm your input spline is 1 inch 23-spline or send us your VIN before ordering.

RST, RXT or RXT HD - which one do I need?

The RST uses organic discs for smooth street engagement and is rated around 800 horsepower. The RXT uses ceramic discs and is rated around 1,100 horsepower, and the RXT HD adds clamp load for the biggest builds. Most street cars with a blower or turbo are well served by the RST.

Is the flywheel included?

Yes. This part number includes McLeod's 8-bolt billet aluminum flywheel, so the clutch and flywheel arrive as one matched unit.

Will the clutch pedal be harder to push?

No. McLeod lists lighter-than-stock pedal feel as a feature of the RST because two discs need less clamp load to hold the same torque.

How do I break in the new clutch?

Drive normally on the street for about 1,200 clutch cycles with traction control off, shifting up and down through the gears. McLeod warns against breaking it in on a chassis dyno.

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