There is no doubt that with a few aftermarket parts, modern Mustangs equipped with the 5.0-liter Coyote engine can generate exponentially more power. With that increase in power often come hardships down the line, specifically in the driveline of the car. Many enthusiasts have voiced complaints about the stock MT82 transmission, which comes on the 2011 and newer Ford Mustangs. Owners mention issues with the transmission not shifting smoothly, and later, that the OE-spec transmission cannot handle the additional power. The good news: there is a plug-and-play, bolt-in solution for this problem, and it is called the TREMEC Magnum XL transmission.
Save The Manuals
For those who crave big power and relish the experience of manually shifting gears, TREMEC’s Magnum XL six-speed manual transmission might be the right answer. TREMEC has enhanced the size of internal components to ensure the transmission is rated for 700 lb-ft of torque.
Mike Kidd, aftermarket business unit manager at TREMEC states, “What truly makes the Magnum XL a bulletproof transmission is the size of some of the internal components. First, the transmission features larger diameter, but narrower, synchronizers, allowing for added face width on speed gears. The increased face-width on the speed gears provides more mesh and greater strength.”
Between the potent power of the Mustang and the robust TREMEC Magnum XL, you will also need a capable clutch to seamlessly transfer the torque from the engine to the transmission. For this, we turned to the experts at McLeod Racing. When it comes to clutches, the market offers numerous choices, often accompanied by confusing information about the right package for a build.
To simplify the world of clutches, we consulted with Billy Mieczkowski, who handles technical sales at McLeod Racing. Before delving into clutches, Mieczkowski emphasized his strong recommendation for swapping out the MT82 for a TREMEC Magnum XL, saying, “That is the first modifications I would recommend for a Mustang. I would swap in the TREMEC before I did an exhaust or even messed with tuning. It is the best mod you can make to a Mustang.”
When it comes to clutches, the array of choices can be overwhelming. Mieczkowski assisted us in navigating the selection process. “The key decisions revolve around the car’s intended use. Is it a street car, drag strip car, autocross car, street and strip car, or full race car?” Mieczkowski advises, “For people who drive their cars and also take them to the drag strip or the autocross, I recommend the RXT line from McLeod Racing. For a 100-percent street car, you can go with our RST. If it is a race car, then choose the RXT 1200.” Mieczkowski highlights that even though the Magnum XL is rated at 700 lb-ft of torque, he often sees cars with 1,000 horsepower using that transmission and the McLeod RXT clutch without encountering any problems.
Another decision to consider when choosing a clutch is whether to go for a single or dual clutch. According to Mieczkowski, “A single clutch is less expensive.” However, he notes, “I see a lot of guys with 400 horsepower cars choose the dual clutch RST Mustang Power Pack because it provides a softer pedal, smoother engaging clutch, and it helps modular motors to shift at peak RPM, so the smaller clutch is less affected by the centrifugal force.”
On The Fly
Besides choosing between a single or dual-disc clutch, McLeod Racing also provides an option for a steel or an aluminum flywheel. Mieczkowski walked us through the differences between the two.
“If you have a steel flywheel on the back of the engine and disengage the clutch pedal at a stop sign without using the throttle, there is enough momentum and weight on the back of the engine with the steel flywheel to begin rolling the car forward.” He continues, “However, if you want the engine to rev quicker at high RPM and choose an aluminum flywheel, the car will stall if you disengage the clutch pedal at a stop sign. You have to modulate the throttle pedal to increase the RPM because the aluminum flywheel is so light it doesn’t have enough momentum to push the car along from a stop.
Therefore, if you are searching for pure performance with cost and driveability not being an issue, then aluminum is your choice. If you want the car to behave like it did from the factory, then choose steel. According to Mieczkowski, “For people who have 80-percent street cars, I primarily recommend steel. For those who want maximum effort, I tell them to go with aluminum”
Often, when you hear about swapping out engines or transmissions, there’s a fair amount of knuckle-busting hard labor and accompanying problems. However, installing a TREMEC Magnum XL with McLeod Racing parts eliminates these issues. This is a true plug-and-play, bolt-in modification. No grinding, no banging on the transmission tunnel, and no sawzall required. The TREMEC Magnum XL comes with the crossmember for the 2011-2017 Ford Mustang and the Quicktime SFI-rated bellhousing.
The other thing that is required when installing the TREMEC is a different length driveshaft. That problem has already been solved by McLeod Racing’s sister company Silver Sport Transmissions, which sells the entire installation kit for the 2011-17 Ford Mustang. The kit includes the bellhousing and crossmember. The installation takes about six hours and the entire kit will set you back a little over $5,000.
A stock slave cylinder can be used, but if you want an upgrade, McLeod Racing sells their own internal throw-out bearing. If you install an aluminum flywheel, you need to perform a crank relearn, which can be done with an aftermarket programmer, or a visit to your local Ford dealership. This is necessary because the engine is measuring the weight of the flywheel and clutch assembly, so it needs to recalibrate for the lighter flywheel. Mieczkowski indicates that all Roush-equipped cars seem to run their own proprietary engine software, so doing the crank relearn would need to be done by Roush technicians.
A couple of other installation tips we learned during the swap: we didn’t remove the exhaust for the removal or installation of the transmission. To remove the transmission, you’d just go straight back and tilt the tail housing up and over the exhaust to clear the bellhousing. Then, you can work on tilting, lowering, and clearing the exhaust. To install the transmission, go up with the tail housing slightly tilted up. Have it go up and over the exhaust until it clears the bellhousing. Then, tilt the input shaft side up and maneuver it into place.
The driveshaft follows a similar approach — remove it from the rear axle side, and when putting it back in, go up and over the exhaust from the rear axle side.
The Solution To Your Transmission Woes
If you own a 2011-17 Ford Mustang and have noticed at the strip, the autocross course, or stoplight to stoplight that your OEM MT82 manual transmission isn’t shift as you want it to, or if your transmission is already a metallic spaghetti underneath your car, you might want to consider an upgrade. The TREMEC Magnum XL six-speed manual transmission with the installation kit from Silver Sport Transmissions is a true plug-and-play, bolt-in upgrade that can significantly enhance your Mustang’s performance.