Ford Performance Friction Modifier by Ford Performance

Ford Performance Friction Modifier

Ensure smooth differential operation in your Mustang or Lightning with this 4-ounce bottle of Ford Perfromance friction modifier additive!

Item #M19546A
MPN# M-19546-A1

Everyday Low Price: $10.99

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  • Ford Mustang - 1979, 1980, 1981, 1982, 1983, 1984, 1985, 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013
  • Ford F-150 SVT Lightning - 1993, 1994, 1995
  • Ford F-150 SVT Lightning - 1999, 2000, 2001, 2002, 2003, 2004
Fitment Notice
  • Fits 1979-2021 Ford Mustang with 7.5 & 8.8 rear (Limited-Slip Traction Lok)
  • Fits 1993-1995 Ford Lightning with 8.8 Traction Lok rear end. 
  • Fits 1999-2004 Ford Lightning with 9.75 Traction Lok rear end


  • Eliminates Rear End Chatter
  • Reduces Limited Slip Noise
  • Promotes Smooth Differential Operation


  • 4 Fluid Ounces
  • Ford Performance Quality
  • Easy Fill Nozzle Cap

 What's in the Box

  • (1) Bottle Of Friction Modifier
  • (1) Cap w/ Nozzle

Ford Performance M-19546-A1 Friction Modifier
Ford Performance M-19546-A1 Friction Modifier is identical to Motorcraft XL3 Friction Modifier. This fluid is a specially formulated additive to provide smooth operation of clutch-type limited-slip differentials. One bottle of friction modifier is required when changing the gear oil in rear ends equipped with Ford traction-lok units. When making a turn, the outer wheels of your Mustang must travel faster than the inner wheels. It is up to the differential to act as a balance arm, establishing constant equilibrium of torques and forces between the left-hand and right-hand driven wheels. In standard (or open) differentials, power is directed to the wheel offering the least resistance. This works well when making a turn, but in a situation where one wheel is lifted off the ground, it causes the suspended wheel to turn while the other remains motionless.

Traction-Lok Differentials
Limited-slip (or positraction) and locking differentials are traction-increasing devices. Locking differentials transfer all available torque to both wheels. The teeth of the spider assembly engage with those on the locker clutch, causing both axle shafts to operate as one. Locking differentials don't allow one drive wheel to spin while the other remains stationary. Instead, they keep both wheels in drive mode, but unlock to permit different wheel speeds when turning. The engaging and disengaging of the teeth on automatic locking differentials often causes a banging and clunking sound. Manual locking differentials usually use an electric motor or vacuum diaphragm to engage the locker, reducing this noise. Limited-slip differentials allow different wheel speeds when turning, but when one wheel loses traction, greater torque is transferred to the wheel offering more resistance. Limited-slip differentials make use of friction between clutch plates, as opposed to the meshing teeth employed by locking differentials. Transferring less torque per side, limited-slip differentials are generally smoother and quieter than locking differentials, but still sometimes "chatter" when transferring torque to the wheel with traction. In your Mustang or Lightning, a friction modifier additive is necessary to reduce this chatter. Ford Perfromance friction modifier is designed to eliminate gear-housing noise and chatter in your drivetrain.

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About This Brand

Ford Performance
Ford Performance - Mustang Ford Racing Parts
Ford Performance Parts is the leader in performance parts and accessories for Mustang and Ford Lightning. is proud to offer Ford Racing Performance Parts for your project. Ford Racing is dedicated to manufacturing the highest quality products offered in the industry. Choose from suspension, exhaust, wheels, and other performance parts at Late Model Restoration. If you want the best for your Mustang or SVT Lightning, look no further than Ford Performance Parts!
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