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Motive Performance Plus 3.73 Gears (99-04 V6)

19 Reviews
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  • Item #21107G99
  • MPN# F7.5-373

  • Market Price $206.79
  • You Save 9% ($18.80)
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  • Superior Quality
  • CNC-Cut from 8620 Gear Steel
  • 3.73 Gear Ratio
  • 7.5" Ring Gear Diameter
  • For Street or Track Use
  • Fits 1999-2004 V6 Mustangs
Improve Performance. Wake up your V6-powered pony for faster acceleration off the line with a set of 3.73 Motive Performance Plus gears. A steeper set of gears will get you into your power band faster for faster launches and more punch off the line.

3.73 Gear Ratio. 3.73 gears are a great combination of performance and fuel economy that's ideal for a daily-driven 'Stang that sees a lot of highway time. If you put a lot of miles on your Pony and don't want to increase your cost at the pump, a 3.73 ratio will still give you the added acceleration you want without compromising fuel economy dramatically.

Superior Construction. These Motive ring and pinon gears are CNC cut from high grade 8620 gear steel, and factory lapped for precision fit. Each set is hardness tested prior to leaving the factory to ensure the highest quality.

Recommended Upgrade. Changing the rear axle gear ratio will throw off the calibration of your Mustangs speedometer, but a Ford Racing Speedometer Recalibration Tool is an inexpensive way to fix this issue.

Application. This Motive Performance Plus Ring and Pinion Gear set will fit all 1999 to 2004 V6 Ford Mustangs equipped with a 7.5" rear end. A master bearing kit is recommended by most installers, especially on high mileage vehicles, see drop down option above.

Installation note. The Ring and Gear Pinion kit will require a notched cross-pin for proper installation.

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.

Fitment: 1999 2000 2001 2002 2003 2004 Details

What's in the Box
  • (1) Ring gear
  • (1) Pinion gear
Installation Info
Will it fit my Mustang?
  • V6 - 99, 00, 01, 02, 03, 04

Most Helpful Reviews

More Get Up And Go!!!!

Bought and had these installed by a professional in my 5 speed 2000 v6 mustang along with the 7.5 28 T-LOK slip differential and felt the difference immediately. A must buy for anyone with a v6 looking ...

Read More
Helpful (1)


I have a lot of mods on my mustang! but this mod wakes it up!!!! I got this plus lsd and a light weight drive shaft! and she takes off!!!!. My mustang is an auto but will chirp tires when shifting LOVE ...

Read More
Helpful (1)

Overall Rating 4.9 out of 5 stars
Read All 19 Reviews

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4 Questions / 8 Answers

Ask a Question

Do you really need a tune after ?


  • Short answer is no. However, you're speedometer will be off. If you go forward with this, I recommend the master install kit and Royal Purple fluid. If using RP, no friction modifier is necessary. Also, after cleaning the mating surfaces on the differential and cover, use black RTV to create a seal and DO NOT use the gasket, as it will almost certainly leak.


    Good Answer (0) (0)

Show 1 more answer Answer This Question I need this answered (1) (0)

will there's gears fit is a stock rear end or do i have to get a bigger rear end?


  • These new gears will fit in your stock rear without any problems. Installing these will throw off your speedo though, so I recommend getting a new tune to correct for that. Also, it's a great idea to get the installation and bearing kit and the necessary gear oil for a perfect install. Combining these gears with an LSD would be an awesome combo for your V6, putting all your power to the pavement and eliminating those 1 wheel burnouts! Best of luck!


    Good Answer (1) (0)

Show 1 more answer Question Resolved

or 4.10 I have a v6 daily driver. Do minimal high way driving. Which set would go best?


  • I personally like 3:73 ratio however if you don't do much highway driving and looking for the most from standing start acceleration then the 4:10 ratio is best.


    Good Answer (0) (0)

Show 2 more answers Question Resolved

I'm thinking about getting this for my 03 auto V6 mustang and was wondering what is everthing I need to install this properly?


  • You will need to purchase the Motive Rear End Installation and Bearing Kit Item #21202 ( along with new rear differential fluid. The Ring and Gear Pinion kit will require a notched cross-pin for proper installation, and the speedometer will have to be re-calibrated as well.


    Good Answer (0) (0)

Question Resolved

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Customer Reviews (19) Write a Review

Overall Rating 4.9

out of 5 stars

Installation Time:Weekend

Installation Cost:$500-$1000

  • Performance Gain 5 5
  • Fit 5 5

  • 5/5

    Installation Time: Shop Install

    Installation Cost: $500-$1000

    October 26, 2014


    I have a lot of mods on my mustang! but this mod wakes it up!!!! I got this plus lsd and a light weight drive shaft! and she takes off!!!!. My mustang is an auto but will chirp tires when shifting LOVE THE POWER!!!!!!!!!!!!!!!!!!!!!!!!!


    Year: 1999 Submodel: V6 powhatan,va

    Helpful (1) (0)

  • 5/5

    January 02, 2011

    More Get Up And Go!!!!

    Bought and had these installed by a professional in my 5 speed 2000 v6 mustang along with the 7.5 28 T-LOK slip differential and felt the difference immediately. A must buy for anyone with a v6 looking for better acceleration and handling, their even better when combined with a custom tune. For those of you who want to buy the gears and the T-LOK and are wondering how much it will cost at a garage to have BOTH installed it will be around $500.00-$600.00 just for installation but worth it.

    Johnathon May

    Helpful (1) (0)

  • 5/5

    January 11, 2011

    big time must

    got this 3.73...came from factory 3.27...2000 v6 mustang 5sp... i only lost 300 rpms..65mph is now 2250 rpms..factory was 1950... definatly is a whole lot quicker getting into the "power band" also got the t-lok with thing i have done so far to this car..well other than getting the wireless tuner for it :) thanks AM !!

    justin p

    Year: 2000 Submodel: V6

    Helpful (8) (0)

  • 5/5

    November 03, 2009

    one word "awsome"

    put gears in,took just a few hours.Did the 500 mile break in.Now i race all over town! I love the new power.Thanks,American Muscle.Im glad i went with the 373,perfect fit for my daily driver!!

    colleen hartman

    Helpful (5) (1)

  • 5/5

    July 08, 2008


    I bought these gears along with the installation kit, and Royal Purple fluid. This really woke the car up. I do a lot of highway driving and noticed no change in noise or fuel economy. An SCT tuner will allow you to correct your speedometer and get some extra power at the same time.

    Ron B

    Helpful (4) (0)

  • 5/5

    June 26, 2008


    These gears are exactly what the title says, nasty! All together it was around $750 for the works, however, I do recommend getting a posi-traction differential. My car is a lot more fun to drive now.

    Tyler Malek

    Helpful (3) (0)

  • 5/5

    May 15, 2011

    Motive Performance Plus 3.73 Gears (99-04 V6)

    I ordered these gears with an install/bearing kit for my 01 V6 Convertible and WOW! what a difference it made. Don't fet me wrong it's still not my GT but it really woke it up! Great upgrade and bang for the buck!


    Year: 2001 Submodel: V6

    Helpful (3) (1)

  • 5/5

    March 24, 2010


    373,perfect fit for my V6 The difference is much, now runs with more power with better acceleration THANK YOU AMERICAN MUSCLE


    Helpful (3) (1)

  • 5/5

    April 19, 2011

    V6 Auto w. TLok

    Major improvement in acceleration. I installed these myself which saves me a lot of money, and it wasnt to hard to install just have to make sure backlash and preload is correct or else they will whine. If your like me and you want hard launches get the 4.10 gears or upgrade the rear end to a 8.8 and get even higher gears. I really like these gears but wished i swapped rear ends and wint with 4.30 gears.


    Year: 2001 Submodel: V6

    Helpful (4) (3)

  • 5/5

    March 16, 2011

    well worth the money

    I added this to my stang along with a ford racing tlok and a 4 bank elim chip. i must say installing all of it was a process. make sure you get the right backlash in the gears and compound mesh and your set. id get professional help if you dont have the tools. great acceleration and performance. makes GTs jealous now


    Year: 2000 Submodel: V6

    Helpful (1) (2)

  • 4/5

    February 17, 2011

    Woke the pony up!

    This was a great product. Made my V6 really fly.. Only thing I didn't like is that it didn't come with and spacers or any of the bearings or crush collar that are pretty much mandatory. I wouldn't recommend doing rhis yourself unless you are a very experienced tech with a hoist. Don't count on finishing it in 1 day either. Took 2 buddies and I 2 7 hr. Days with a hoist. Very pleased with the product thus far. Just doin the 500 mile break in.

    Brad Coxe

    Helpful (1) (2)

  • 5/5

    November 08, 2007

    great gears!

    These gears are awesome. They don\'t whine or anything, I have about 5-10k miles on them so far and no problems! it woke my sixer up.


    Helpful (0) (1)

  • 5/5

    Installation Time: Full Day

    May 20, 2014


    This product came in fast and looks great, there were no signs of it being used. I bought it for my son's mustang which he is still working on, just waiting for the differential to come in as the first one we bought from eBay was defected so we returned it and then bought another from American muscle! Should be in today! Can't wait to have them put it on to start driving my son's musty again!!


    Year: 2000 Submodel: V6 Chicago, Illinois

    Helpful (0) (0)

  • 5/5

    Installation Time: Shop Install

    April 18, 2012


    I got these for my 2003 v6 and it was definitely worth it. Having these put in was definitely one of the best installs i have done so far. Thanks


    Year: 2003 Submodel: V6 McPherson, KS 67460, USA

    Helpful (0) (0)

  • 5/5

    February 19, 2010

    Great Mod

    Great mod albeit expensive with POSI, bearing kit and a $ 430 prof. installation. It was worth waiting and saving. It really gives a boost to your V6. After long search on Inet, AM provided the best prices for these parts.

    Fabian Hug

    Helpful (0) (0)

  • 5/5

    May 29, 2009

    less slow!

    I had to rebuild the rear end of my mustang so I figured I would throw in some lower gears to get some more pep from my slow single port. I am very happy with the result, the acceleration is much better. The down side is that at 65mph im at 2500rpm (5spd). At least it keeps me from getting speeding tickets on the freeway.


    Helpful (0) (0)

  • 5/5

    May 15, 2009

    A must!

    This product is a definite MUST a long with the T-lock to V6 enthusiasts! If you want more bang for your buck, then this is surely your item!


    Helpful (0) (0)

  • 5/5

    November 18, 2008

    One beefy ring

    Got this along with my T lock. Talk about one solid piece of equipment!


    Helpful (0) (0)

  • 5/5

    June 15, 2008

    Worth It, Does The Job

    I bought 3.73 Gears for my V6, I decided to stay with the 7.5in rear. But I must say, the gears do a VERY noticeable difference in acceleration off the line and in the low-mid RPM range. These gears wont hurt your MPG either, it will be near stock. Dont waste your money on FRPP gears or others, Motive Performance is an inexpensive and reliable way to go to upgrade gears. Also, gears only whine if the technician doesnt take the time to align them correctly. Definitely recommended though.

    Andrew F.

    Helpful (0) (0)

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