Magnum XL 6-Speed KIT 2.66 first .80/.63 OD/ TUKT16901



TUET16901 TREMEC T-56 Magnum XL 6-speed Transmission Kit
for the 2005-2010 Ford Mustangs

  • Gear Ratios 2.66, 1.78, 1.30, 1, .80, .63
  • 26 spline input, 31 spline output Shafts
  • Torque rated 700+ft/lbs
  • SFI 6.1 Certified bellhousing
  • Direct mounted shifter
  • Analog Electric Speedometer Sensor 


Modern Driveline was the first to install a Magnum XL into both V8 and V6 Mustangs and has the most in-depth knowledge and parts in the industry!

Don’t make the mistake of purchasing somewhere else only to be left with incomplete parts and advice.
All our products are backed with Lifetime technical support.

See us first for your MT-82 to Magnum XL upgrade.
Magnum transmissions are the strongest 6-speed manuals ever built.
They can withstand up to 700 ft.-lbs. of torque, with gears featuring substantially increased face widths

We extend the manufacturer’s warranty for an extra year and that is from the date of installation.

TREMEC® T56 MAGNUM XL 6-Speed S197/S555 Mustang Double Overdrive Transmission

TUKT16901 with 2.66 first and .80/.63 OD

Introduced to the marketplace in 2012, the Magnum XL is a continuation of the popular Magnum 6-speed series. Featuring all the most important content from the original Magnum, the XL retains its brute strength and sophistication but eliminates its multiple shifter locations and dual speedo outputs

The Magnum XL  adds an extended-length tail section designed to eliminate the clumsy semi-remote shifter found in many popular late-model applications.
Currently available only for 2005-up S197 & S555 Mustangs, the Magnum XL includes an SFI-approved steel bell-housing with an enclosure plate, a swap-specific cross-member, and an OE-quality transmission mount.
For strength purposes, the Magnum XL also requires a 26-spline clutch and one-piece driveshaft (sold separately). Some applications may require speedometer e-calibration via ECU tuning or through the use of a separate signal converter.

For a complete Tremec T56 Magnum XL install package, Contact us for an installation package that includes, Flywheel, clutches, module/harnessing, driveshaft, oil, and installation instructions.

Features & Benefits:

  • 85mm center distance.
  • 700 lb-ft effective torque capacity.
  • Direct shift aluminum shifter for smooth, positive shift action.
  • SFI 6.1 certified Scatterproof Bellhousing
  • Triple cone synchronizers on gears 1-4, double cone synchronizers on gears 5-6, as well as reverse.
  • Accurate, smooth, high-rpm shift capabilities.
  • 26 Spline input shaft
  • 31 Spline output shaft
  • Direct-Fit replacement crossmember
  • Electric analog sensor speedometer.

Part Number
Application Torque Cap.
Gear Ratio Chart
1st 2nd 3rd 4th 5th 6th Rev
TUET16886 FORD 700 2.66 1.78  1.30 1.00 0.80 0.63 2.90
TUET11940 FORD 700 2.97 2.10 1.46 1.00 0.80 0.63 2.90
TUET12021 FORD 700 2.97 2.10 1.46 1.00 0.80 0.63 2.90
TUET16901 FORD 700 2.66 1.78 1.30 1.00 0.80 0.63 2.90


HOW TO: T56 Magnum XL 6-Speed Swap a 2011-current Mustang GT

HOW TO: Motorz TV Feature Upgrade 2008 Mustang GT to a T-56 Magnum XL Trans.

2011-current V6 Mustang T56 Magnum XL 6-speed Swap

05-2010 Mustang Conversions

Additional information

Weight 3760 oz
Dimensions 46.5 × 22 × 20 in


Hover over image to enlarge



  1. Extended-length (XL) extension housing
  2. Shifter location that mimics several late-model applications
  3. Reverse inhibitor solenoid
  4. Electronic speedometer output
  5. Fluid drain ports
  6. Common T56 style bolt pattern
  7. Mounting pad for OEM style hydraulic slave or aftermarket guide tube
  8. Clutch fork exit window
  9. Unique isolator style shifter for reduced noise, vibration & harshness (NVH)
  10. Reverse light switch
  11. Slip yoke output
  12. Trans mount location




FORD MODULAR 18.70 / 22.8 / 26.4 5.64″ 26.3″ 33.6″ 3.1″ 38.4 2.75″ TNCM1078



Driving Techniques
A 500-mile break-in period will prevent premature wear and possible damage to the transmission. During the
break-in period, you must avoid high RPM shifts and “drag” starts. The clutch must be fully disengaged to shift
the transmission. Do not use excessive force when shifting the transmission. If you experience clash shifts
(grinding), check clutch travel to ensure proper air-gap is achieved. Another possible cause of clash shifting is
improper transmission installation (excessive driveline angle / resulting in poor driveline alignment). Do not hold
the transmission in gear by applying force on the shifter. This will damage the pads on the shift forks and may
result in significant damage to the transmission.





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