Magnum XL 6-Speed Transmission Kit

The TREMEC Magnum XL 6-speed transmission kit is a high-performance upgrade designed to replace the factory MT-82 and TR-3650 transmissions in 2005-2019 Ford Mustangs, addressing their known weaknesses under power and vague shift feel. Built from the TR-6060 foundation, this kit offers a significant performance improvement. A key upgrade is the extended-length tail section, which positions the shifter directly on the transmission case. This rigid, direct-mount aluminum shifter provides vastly improved performance and quicker shifts compared to the binding-prone factory semi-remote setups. The 2.66 close-ratio gear set is optimized for high-horsepower builds, complemented by double overdrive ratios (.80 fifth and .63 sixth) to keep forced induction engines in their powerband during highway cruising. Engineering highlights include 85mm center distance gearing with increased face widths and laser-beam welded construction for precise tooth control. Triple cone synchronizers on gears 1-4 and double cone synchronizers on gears 5-6 plus reverse ensure accurate, smooth shifts even at high RPMs. The kit comes with an SFI 6.1 certified steel scatterproof bellhousing for competition safety, a swap-specific steel crossmember, and an OE-quality rubber transmission mount for direct-fit installation. It reuses the OEM hydraulic clutch release system. This kit is compatible with 2005-2019 S197 and S550 Mustangs and requires a 26-spline clutch disc and a one-piece driveshaft, which are sold separately. While 2005-2010 models are direct plug-and-play for speedometer function, 2011+ models may necessitate speedometer recalibration via ECU tuning or a signal converter. The transmission uses Dexron III ATF. Modern Driveline extends the manufacturer's warranty for an additional year from the installation date and provides lifetime technical support.