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Ford Performance Friction Modifier (79-14 All)

Item 50377
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      Review & Installation Video

      Hey guys, today we're gonna be taking a look at the Ford Performance Friction Modifier for all 1979 to 2014 Mustangs. If you didn't know already, friction modifier is an additive. It's added to lubricants to help reduce friction and therefore wear and tear.This friction modifier is made to be paired with gear oil, the kind that you fill your rear differential with. Friction modifier is recommended to be added to the rear gear oil for limited-slip diffs that have clutch pads. Of course, it will help with wear and tear and smooth operation. This friction modifier is made by Ford Performance but is compatible with other brands and gear oil.It costs about 11 bucks and this is a 3.8 fluid ounce bottle.Friction modifier is always going to be a good idea to add to your rear gear oil. Not only can it be a preventative and help keep away wear and tear, but it can also help if you're already having issues. It can reduce gear whine and chatter, so some aftermarket gear rears can be noisy and whine a lot, the friction modifier will help with that and quiet the gears down. Any time you're filling up gear fluid, whether you're just flushing it, you're installing a new rear diff, you're doing a rebuild, or you're swapping your gears, you'll always wanna grab some friction modifier to throw in the diff with the gear oil.If you're adding friction modifier though, just keep in mind that you should add it to fresh gear oil.You shouldn't really top used gear oil with modifier. You should always flush completely and refill with gear oil and the friction modifier. The friction modifier needs to be a ratio of the gear oil, not a replacement for it. Friction modifiers are known to be a must-have for anyone with an LSD that uses clutch pads.If you're interested in the Ford Performance Friction Modifier, you can always check it out more online right here at

      Product Information

      Features, Description, Reviews, Q&A, Specs & Installation


      • Perfect for Gear Swaps
      • Reduces Gear Whine and Chatter
      • 3.8 fl oz Bottle
      • For All 1979 to 2014 Mustangs


      Perfect For Gear Swaps. Ford Racing's Friction Modifier is a specially formulated additive to provide smooth operation of clutch-type limited-slip differentials, perfect for gear swaps.

      Legendary Ford Racing Quality. When you're adding performance parts to your Pony, you can't go wrong by installing parts from the folks that know it best. Ford Racing's legendary quality ensures years of hassle-free use.

      Ford Racing Friction Modifier is recommended for use in 1979 to 2014 Mustangs and is compatible with other brands of gear oil. One bottle is required for rear ends equipped with Ford traction-lock units.

      Fitment: 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 2014

      MPN# M-19546-A12

      CA Residents: WARNING: Cancer and Reproductive Harm -


      Customer Reviews (84)

      Write a Review

      Ratings Summary

      4.8 out of 5 overall rating from 84 customers

      Installation Time: Less than 1 Hour

      Installation Cost: $100-$250

      • February 24, 2020

        5 2013 V6 - Yfntony706 Installation Time: Less than 1 Hour

        Friction modifier

        Great add in to your read end when changing out gears!

        Helpful (0)
      • February 16, 2020

        5 2010 GT - DaveS197 Installation Time: Less than 1 Hour

        Must have

        This additive is a must use for posi gear lube replacement or change. Always use it.

        Helpful (0)
      • January 09, 2020

        4 2008 GT - Fbmustang2008 Installation Time: Less than 1 Hour

        OEM fluid

        Great product! OEM quality. Put in a 2008 Mustang GT/CS with over 250,000 miles after installing a Ford Performance Ring and Pinion Installation Kit w/ High Torque Bearing - 8.8 in. (11-14 V6; 86-14 V8, Excluding 13-14 GT500) and the Ford Performance Traction-LOK Limited Slip Differential w/ Carbon Discs - 31 Spline 8.8 in.

        Helpful (0)
      • December 29, 2019

        5 2003 GT - Bitty


        There may be several others on the aftermarket but there’s nothing quite as good as the factory performance products for a traction lock Ford differential

        Helpful (0)
      • December 17, 2019

        5 2002 GT - ElvinC Installation Time: Less than 1 Hour

        Friction modifier

        Simple, easy, and affordable. Works just as described.

        Helpful (0)
      • December 15, 2019

        5 2006 GT - Eddie

        Works great!!!

        Another great purchase from American Muscle!! Rear end is now quiet as a mouse

        Helpful (0)
      • November 27, 2019

        5 2002 GT - JUAREZ Installation Time: Less than 1 Hour

        Ford Performance Friction Modifier

        The product seems it does it's job. Just added it to the differential. Not sure if it will makes a difference but I hope it will have an impact on the long run.

        Helpful (0)
      • October 26, 2019

        5 1993 GT - Trigr1 Installation Time: Afternoon

        Needed for install

        Needed for gear install ..........................................

        Helpful (0)
      • August 20, 2019

        5 2007 GT - ChristopherS Installation Time: Less than 1 Hour

        Great product

        Works as it should no problems. What can you really say about it.

        Helpful (0)
      • August 19, 2019

        5 2016 EcoBoost - Nelly90210 Installation Time: Less than 1 Hour

        Works as advertised

        Works great. It helped quiet down my rear differential

        Helpful (1)

      Questions & Answers (9 answers)

      5 Top Rated Questions

      I have a 2014 GT premium 5.0 with an automatic. Would you recommend the use of this product when changing the gear oil? Thank you.

      • We do recommend using friction modifier when changing your Mustangs ger oil!

      Helpful (7)

      Can i add this to my car without having done a gear change or replacing the gear oil

      • I would not recommend adding Ford Performance Friction Modifier unless you are changing your gear oil, it is added in as a ratio with gear oil.

      Helpful (2)

      Application I've scoured the internet looking for recommended methods of application and found nothing. Do I apply this gear by gear with a brush or do I just toss this in at the same time with the diff fluid?

      • It's designed to be poured directly in to transaxle case using a limited slip differential also referred to as a "Posi" meaning both wheels spin when power is applied. I would suggest pour entire bottle in first then pumping in your new fluid fill just below the fill hole plug. Check your year and model for specfication on filling level and fluid requirements. You may notice a faint noise from the differential for a few days until the new fluid and additive impregnate the clutch pads and it will go away nothing to worry about.

      Helpful (2) Show 1 more answer

      2007 GT 8.8 Rear axle My problem: only one wheel spins in high throttle. The clutch slips. Is this a thing that prevents clutch slip? Or is it only the noise that is reduced?

      • Unfortunately Ford Performance Friction Modifier is used to provide additional lubrication to the gears in the differential, however it would not prevent clutch slip. Clutch slip is usually the result of the clutch and flywheel unable to transfer torque to the drive-train. The only solution would be to replace the clutch and flywheel in most cases. Feel free to give our customer service department a call if you have any additional questions!

      Helpful (1)

      Can I use it with ford mustang ecoboost 2017?

      • No, this is designed for the 79-14 specifically.

      Helpful (0)
      Post Your Question
      4 More Questions
      This friction modifier is good just for differentials or you can add when you change gear oil in gear box to 0 answer
      Hello I have smal gear whine between 40-60 mls help this product? maybe 2 bottles 1 answer
      Is friction modifier good for a manual transmission gear box? 1 answer
      do i need to use this stuff i swapped gears about 1 year ago and used friction modifier.....i want to change rear end fluid i need to use the friction modifier ??? thanks 1 answer

      Installation & What's in the Box

      What's in the Box

      • (1) 3.8 fluid oz bottle

      Tech Specs

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