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Ford Performance 3.73 Gears and Install Kit (10-14 V8; 11-14 V6)

Item 100573
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    Features, Video & Details

    • Money Saving Combo Kit
    • Ford Racing 3.73 Gears - 8.8"
    • Ford 8.8in Rear Gear Pinion Bearing
    • Motive 8.8" Rear End Installation and Bearing Kit
    • 1 Bottle of Ford Racing Friction Modifier
    • 2 Quarts of Royal Purple Max Gear 75w140 Gear Oil
    • Fits 2005-2014 V8 and 2011-2014 V6 Mustangs with 8.8" Solid Rear Axle

    Review & Installation Video

    Review & Install Video

    Improve ET's and low end torque. Are you looking to get more low end grunt off the line and lower ET's at the same time? Then look no further than installing a set of steeper gears in your Pony. This Ford Racing Ring and Pinion Gears are perfect for street, road, or race use.

    Complete Kit. This Ford Racing Gear and Installation Kit comes complete with all the components needed to swap out your ring and pinion gear. It includes Ring gear, Pinion gear, inner rear gear pinion bearing, 1 bottle of Friction Modifier, 2 bottles of 75w140 Gear Oil, gaskets, seals, shims, bearings and all the required hardware.

    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.

    Recommended Upgrade. Changing the rear axle gear ratio will throw off the calibration of your Mustangs speedometer, but a Ford Racing Speedometer Recalibration Tool or a Bama SF4/X4 Power Flash Tuner is a quick and easy way to fix this issue.

    Application. This Ford Racing 3.73 Rear Gear and Installation Kit is designed for use with 8.8in solid rear axle equipped Mustangs, including the 2005-2014 GT, Bullitt, BOSS, Shelby GT500 and 2011-2014 V6 models.

    Application Note: Does not fit 2013 Boss or 2013-2014 Shelby GT500 Mustangs with axle codes S-215-D and S-219-D.

    Technical Note. Installation costs will vary, but a good rule of thumb is between $250 and $300. Be sure to work with a reliable shop that you trust for installations. You can also save money on your installation labor by having your Trac-Lok rebuilt at the same time as your gears are installed, see drop down option above.

    Fitment: 2010 2011 2012 2013 2014 Details

    MPN# 100573

    CA Residents: WARNING: Cancer and Reproductive Harm - www.P65Warnings.ca.gov

    What's in the Box
    • (1) Ring gear
    • (1) Pinion gear
    • (1) Rear Gear Pinion Bearing
    • (1) 3.8 fluid oz bottle of Friction Modifier
    • (2) one quart bottle of Royal Purple Max Gear 75w140 Gear Oil
    • Front & Rear Pinion Bearing
    • Pinion Seal
    • Carrier Bearings
    • Carrier Shims
    • Differential Bearings
    • Crush Sleeve
    • Pinion Nut
    • Cover Gasket
    • Ring Gear Bolts
    • Brush
    • Gear Marking Compound
    • Loctite
    Installation Info
    Will it fit my Mustang?
    • Boss 302 - 12, 13
    • GT - 10, 11, 12, 13, 14
    • GT500 - 10, 11, 12
    • V6 - 11, 12, 13, 14

    Does not fit 2013 Boss or 2013-2014 Shelby GT500 Mustangs with axle codes S-215-D and S-219-D.

      Customer Photos (8) Submit Your Photo

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        Questions & Answers (25)

        5 Top Rated Questions

        I am thinking about upgrading to this kit for my 2012 GT. It currently is running on a tune 24/7 because of my boss 302 intake and it is tuned for the stock 3.15 gears. I plan on having this done professionally, I will get a new tune for these 3.73 gears before i take it in. Should i tell the shop not to start the car until i have the new tune for these gears installed?

        • Naw it will be alright your speedo will be off by a few mph's that's all. If you have a manual car I would go 4.10 only if you don't drive it ever day with that 6 gear you almost can't tell. I got that in my car now and let me tell you it's amazing out of the gate......

        Helpful (9)

        would these gears fit my stock carrier from my 2014 mustang v6 premium that carried a 2.73?

        • This certainly would fit your 14 V6.

        Helpful (2)

        Hi, I have Gt 2011 with stock gears 3.15 my question is wich one is better in drag racing from 0 KM , 40 KM , and 60 KM the 3.55 or 3.73 ? Thanks.

        • The Ford Performance 3.73 Gears and Install Kit will be able to get you off the line much faster than the 3.55 gears will. However, the 3.55 gear ratio will keep pulling at higher speeds than the 3.73s for a longer stretch.

        Helpful (1)

        if I were to install these gears would I need to get new axles as well or will stock axles work just as good?

        • The Stock axles will absolutely work with the Ford Performance 3.73 Gears and Install Kit without any issues.

        Helpful (1)

        "Ford Performance 3.73 Gears and Install Kit (10-14 V8; 11-14 V6)." Hi, i bought these for my 14 v6, still in the box. I'm thinking about purchasing a 17 v6, will this gear kit fit in the 17 v6? Thx

        • This Ford Racing 3.73 Rear Gear and Installation Kit is designed for use with 8.8in solid rear axle models and will not work with the 15+ models due to the independent rear end.

        Helpful (1)
        Post Your Question
        10 More Questions
        If I purchase this kit for a 2010 GT, do I still need to purchase the "Rear Gear Pinion Bearing" Item#394003? I remember seeing a video here on AM, and Steph said this would be necessary for the 2010 because the design had changed. Or is there a complete kit for the 2010's specifically? 1 answer
        For my vehicle and set up, 2014 V6 mustang what would be better 3.55 or 3.73 gears I'm am running a custom tune on 91 premium gas, and looking for a little bit better fuel economy. So what would be the better option for my setup 1 answer
        what's the weight of "Ford Performance 3.73 Gears and Install Kit" package? 1 answer
        I have a 2013 V6 3.7L will this be ok to install and drive on every day? 1 answer
        Will this kit work with a six speed manual Mustang 2012 V6? 0 answer
        Putting these in a 14Gt... Do I need to do a tune when you re-gear? 1 answer
        I can't find a shop in my area that will install this for a reasonable price. If I brought my car to you guys could you install it? 1 answer
        Would i Need the whole install kit if i have 73k miles on my car? 1 answer
        Will this kit work for 2010 4.0 v6. 1 answer
        If I install these 3.73s, do I have to change the axles since I'm running on bigger gears? 1 answer

          Customer Reviews (84) Write a Review

          Overall Rating 4.7

          out of 5 stars

          Installation Time:Weekend

          Installation Cost:$250-$500

          • Performance Gain 4.833333 4.8
          • Fit 4.730769 4.7



          • 1/5

            Installation Time: Afternoon

            August 24, 2019

            complete junk and no warranty

            Let me start by saying I am a Master Tech. I cannot get a good pattern on this gear set. I can get almost a good pattern but no contact in the middle no matter what i set the pinion depth or backlash at. When requesting warranty i was referred to Fords web site and found that Ford Performance parts are sold "as is" with no warranty, NO WARRANTY AT ALL. Now i have a $300 boat anchor.

            nothappyatall

            Year: 2014 Submodel: V6

            Helpful (1)

          • 5/5

            Installation Time: Shop Install

            Installation Cost: $500-$1000

            May 22, 2019

            So much for 1st gear

            I have been driving my V6 around with this kit installed for about a month now and I'll tell you what....forget you even have a 1st gear. It's totally useless. I also had the driveshaft upgraded and a dyno tune. I actually saw my city fuel mileage go up since I cruise around in 5th or 6th gear instead of 3rd or 4th. Hwy mileage only went down to about 28mpg. It turns out, the speed shop I went to for the install recommends to replace the MT-83 transmission down the road with a T-56XL. AM has one but only for the GT. The V6 version has slightly different gear ratios, idk if there are any other differences. Definitely an expensive upgrade but in the event of a messed up trans from track day driving, probably worth it, plus you'd gain a small amount of fuel mileage back since both 5th and 6th are OD gears in the T-56XL.

            JayB

            Year: 2011 Submodel: V6

            Helpful (4)

          • 5/5

            Installation Time: Weekend

            November 12, 2018

            Great mod!

            I was planning on upgrading my 3.15 gears to 3.73 after winter in the summer. However, my car had other plans. I developed some whining and issues with the rear. Instead of fixing the issue which would have been way cheaper. I decided since I am going to open it up I might as well upgrade. I have a few things to mentions if you are doing it yourself. This job is indeed a very messy job and requires a lot of work. We had done it on jacks, but I recommend finding a shop that can do it for a fair price. It is truly not worth doing it yourself. Also, you will need many specialty tools. Many of which you have to rent and some I had to purchase. Even with the right tools, there is still a lot you have to improvise yourself. Another mention is that you will need to buy a third bottle since you need to lube up the bearings as well as fill up the differential. Unfortunately, when I was purchasing these gears this kit was out of stock. American muscle was only missing the modifier which you don't need since royal purple has it already in it's formula. And they refused to send me the rest of the kit so I had to pay a lot more money to piece it together. When it comes to performance the car pulls very hard specifically if you have a tune on the car. I was quite surprised how the car had improved. I would recommend this mod hands down, but you really have to decide if you want to install it yourself.

            LukaszF

            Year: 2013 Submodel: GT

            Helpful (16)

          • 5/5

            August 09, 2018

            A must mod for a V6

            My 2014 is a completely different Mustang after having the 3.73 gears installed and a Bama tune. Super fun to drive now. Thanks American Muscle!

            GeorgeS

            Year: 2014 Submodel: V6

            Helpful (16)

          • 5/5

            Installation Time: Shop Install

            Installation Cost: $1000+

            July 29, 2018

            great gears

            Gears went in no problem. Tuned it after I had it installed and made a huge difference

            WilliamC

            Year: 2013 Submodel: GT

            Helpful (11)

          • 5/5

            Installation Time: Shop Install

            Installation Cost: $250-$500

            July 21, 2018

            Must buy

            Bought gears back in 2016 December had Ford's techs install them if u have a mustang v6 u will love what these 3.73's gears does for your v6 outstanding performance and excelleration from a stand still I highly recommend the 3.73 gears would also recommend getting a tune or calibration tool for speedometer

            battlezack

            Year: 2014 Submodel: V6

            Helpful (14)

          • 5/5

            Installation Time: Shop Install

            Installation Cost: $250-$500

            May 12, 2018

            One of the best mods!

            Highly recommend for that edge over others. The response is much quicker. That being said a few tips when getting them installed...1) You are going to need an additional quart of the royal purple oil to fill it correctly 2) do not forget there's a break in period that is recommended. You should drive for about 20-30 minutes then let it cool. And repeat the process several times before opening it up full throttle. 3) The speedometer will be off. Mine was 15mph faster than actual speed and I've seen others including mine become even more inaccurate the faster you go. Over all great product for the price!

            NathanC

            Year: 2014 Submodel: V6

            Helpful (18)

          • 1/5

            Installation Time: Shop Install

            Installation Cost: $500-$1000

            May 10, 2018

            Graet addition

            Really woke up my v-6, the 3.73 gears and with my MPT tune the car pulls hard in every gear. Best addition yet.

            EverettH

            Year: 2012 Submodel: V6

            Helpful (12)

          • 5/5

            Installation Time: Afternoon

            April 27, 2018

            Gears

            Having a skilled background is needed to install, if you have one it’s only a couple hours to install. Performance gains are great for street or strip.

            JeffD

            Year: 2012 Submodel: GT

            Helpful (13)

          • 5/5

            Installation Time: Shop Install

            Installation Cost: $250-$500

            April 25, 2018

            373..! V6

            Best bang for your dollar this mod will keep you in your power band make the car alive and highly responsive

            S1972014

            Year: 2014 Submodel: V6

            Helpful (16)

          • 5/5

            Installation Time: Afternoon

            February 14, 2018

            Broke-back Gear...

            Went together like a clock, thanks Kevin for your compassionate and thorough assistance...jhf

            JohnF

            Year: 2012 Submodel: GT

            Helpful (12)

          • 5/5

            Installation Time: Shop Install

            Installation Cost: $250-$500

            January 31, 2018

            Oustanding

            Absolutely made a difference on acceleration. Very pleased. Per the reviews, I bought the additional bottle of gear grease. Everything came out perfect. I don't even notice any MPG difference.

            Ryan

            Year: 2014 Submodel: GT

            Helpful (13)

          • 5/5

            Installation Time: Shop Install

            January 22, 2018

            good purchase

            received just what i ordered. customer sevice was very helpful

            AAndrew33

            Year: 2012 Submodel: V6

            Helpful (12)

          • 5/5

            Installation Time: Shop Install

            Installation Cost: $500-$1000

            January 11, 2018

            3.73 Ford Performance Gears

            Installed in my 2014 GT/CS Convertible which came with 3.15 gears. Good mileage but sluggish off the line. Had Ford install some Ford Performance 3.73 rear gears. Wow what a difference. It woke my Automatic up. Shifts harder, grabs the road, and mileage suffered only a few mpg's. Love it.

            Doug

            Year: 2014 Submodel: GT

            Helpful (14)

          • 5/5

            Installation Time: Shop Install

            Installation Cost: $250-$500

            January 07, 2018

            Must have MOD...

            My 2011 3.7 with 3:31s seemed lazy, but now with 3:73s it feels like I’m driving a more powerful car because there’s instant throttle response, power and she leaves much faster and throws her rear end out a little. It’s a blast to show off your torque at times. These gears compliment my automatic making smoother transitions between gears with less RPMs, and combined with shorty headers and Flowmasters instantly bring a big smile to my face! These gears will transform your 3.7 into a formidable street contender and you’ll have more fun than a roller coaster.

            DJMustang

            Year: 2011 Submodel: V6

            Helpful (21)

          • 5/5

            Installation Time: Shop Install

            Installation Cost: $100-$250

            September 12, 2017

            Great product

            These gears are fantastic! The car pulls way harder and is much quicker off the line. The only downside is whenever I go above 90mph, the car starts to shake. Other than that, great purchase.

            Gilby

            Year: 2014 Submodel: V6

            Helpful (15)

          • 5/5

            Installation Time: Shop Install

            Installation Cost: $250-$500

            July 11, 2017

            Totally different car now

            These 3.73 gears change the hole car. The car leaves so much faster and throws the rear end out a little in the 1-2 shift in the auto when accompanied with a Bama race tune. Would 100 recommend this product.

            BM3

            Year: 2014 Submodel: V6

            Helpful (21)

          • 5/5

            June 29, 2017

            Worth the money!

            I've noticed a big difference in acceleration! I have off road x pipe,85mm throttle body, roush intake, res delete and tune and this paired perfectly. Definitely worth the money.

            Chris

            Year: 2013 Submodel: GT

            Helpful (15)

          • 5/5

            Installation Time: Afternoon

            June 21, 2017

            MAKES ALL THE DIFFERENCE!!!

            I threw these in along with a cold air intake and a Bama tuner. The difference is HUGE! This is the way a GT should come from the factory! Makes me smile every time I get on it.

            JoshC

            Year: 2011 Submodel: GT

            Helpful (15)

          • 5/5

            Installation Time: Full Day

            June 13, 2017

            Game changer

            You can definitely feel the improvement to your car! the gears wake up the mustang and really help you get through the gears. MPG will drop by 2-4 especially on the highway with 85 MPH being around 3k RPM in 6th gear. Power is totally worth the MPG drop if that's what you're going for. 250 for the kit and had a Ford tech friend install it for 180, amazing bang for your buck.

            Thomas

            Year: 2014 Submodel: V6

            Helpful (15)

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