McLeod RXT Twin Disc Clutch Kit 18-19 Ford Mustang RXT 1 x 26 Spline 0 Bal w/164T 8 Bolt AL...

Swapping a 2018 or later Mustang GT away from the factory six-speed is usually part of a bigger build: a blower or turbos, a stronger gearbox, and a clutch that has to hold all of it. McLeod part number 6333807M is the RXT twin disc clutch and billet aluminum flywheel package for the Gen 3 Coyote 5.0L with the 8-bolt crank, made for a transmission with a 1-1/8 in. by 26 spline input shaft. It is the kit to buy when the gearbox behind your S550 is no longer the stock one and the clutch needs to match it.

What the RXT twin clutch does behind a 2018-up Coyote

The RXT is McLeod's ceramic twin disc street clutch. Two ceramic lined discs share the pressure plate's clamp load with a floater plate between them, so the assembly holds a lot more torque than one disc of the same diameter while keeping a pedal that McLeod calls lighter than stock. McLeod rates the RXT street twin for builds up to roughly 1,100 horsepower, aimed at supercharged, turbocharged and nitrous cars that still get driven on the street. The pressure plate is strap drive.

In this part number the clutch comes on a dedicated billet aluminum flywheel drilled for the 8-bolt Coyote crank, with a 164 tooth ring gear and zero external balance. The difference from McLeod's 2018-up GT kits for the stock gearbox is the disc hub: these discs are splined 1-1/8 x 26 instead of the factory 1 in. x 23 metric spline. The aluminum flywheel sheds a lot of mass compared with the factory dual mass unit, so revs climb and fall faster. Plan on a little more throttle when pulling away and some gear rattle at idle; our dual mass vs single mass flywheel guide explains why.

Signs your current clutch is the weak link

• Engine speed flares on a hard shift or in a high gear pull once boost comes in
• Slip that gets worse as the clutch heats up during repeated passes
• Chatter on launch from a glazed disc or a heat checked flywheel face
• Engagement point creeping toward the top of the pedal
• A new gearbox install that needs a 26 spline disc to mate with the input shaft

How to confirm before ordering

Rule out the hydraulics first. A leaking slave, air in the line or a reservoir that keeps dropping will stop the clutch from fully clamping or fully releasing, and either one feels like a bad clutch. Then do a controlled high gear roll-on and watch for rpm climbing faster than road speed. Our clutch slipping guide covers both checks, and hard to shift into gear covers release problems. For a whole-job budget, see our manual vs automatic repair cost guide.

Fitment

Our listing title says 2018-2019 Mustang, while McLeod's own catalog text for 6333807M covers the 2018-2023 Mustang 5.0L with the 8-bolt crank and 1-1/8 x 26 spline. Spline is the deciding detail. The factory MT82 in the 2018-up GT uses a 1 x 23 metric input, so a car still on its original gearbox needs the RXT twin for the 1 x 23 spline instead. Count the input shaft splines and measure its diameter, confirm the 164 tooth starter engagement, and send us the year, VIN and gearbox model if anything is in doubt. If you want organic discs for a softer street engagement on the same 26 spline setup, look at the McLeod RST twin for 18-23 Mustang, 1-1/8 x 26. More options are in our rebuild kits category.

Install notes

• Expect the pressure plate, two ceramic discs, floater plate, aluminum flywheel and alignment tool. A release bearing is not part of the clutch assembly, so plan the release system that matches your gearbox and bellhousing.
• McLeod's twin disc instructions call for the discs to be stacked with their alignment marks lined up and centered on the tool, then the pressure plate nuts brought to 25 ft-lb and then 35 ft-lb in a star pattern without thread locker.
• Fit a new pilot bearing sized for the new input shaft. The Lisle 55600 pilot bushing remover pulls the old one cleanly.
• Use new flywheel bolts at the factory torque, bleed the hydraulics until the pedal is firm, and give the ceramic discs about 1,200 gentle street engagements before hard launches.

Will 6333807M fit my 2018-2023 Mustang GT with the stock six-speed?

No. The stock MT82 in the 2018-up GT uses a 1 in. x 23 metric spline input. This kit has 1-1/8 x 26 spline discs for a car that has been swapped to a gearbox with that input. For the stock gearbox, use McLeod's 1 x 23 spline RXT twin.

What is the difference between RXT and RST?

Both are McLeod twin disc street clutches. The RXT uses ceramic discs and is rated by McLeod for up to about 1,100 horsepower. The RST uses organic discs for smoother, more forgiving engagement at a lower power level.

Does the kit include a flywheel and release bearing?

It includes a dedicated billet aluminum flywheel for the 8-bolt Coyote crank with a 164 tooth ring gear and zero balance. A release bearing is not part of the clutch package, so match the bearing to your gearbox and bellhousing.

Will an aluminum flywheel be noisy on the street?

Some gear rattle at idle is normal once the factory dual mass flywheel is gone, and you need a bit more throttle pulling away from a stop. Most owners get used to it within a few drives.

How do I break in the RXT clutch?

McLeod recommends roughly 1,200 normal street engagements before launches or full power shifts. Do not do the break-in on a chassis dyno.

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