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Ford Performance 3.73 Gears and Install Kit (86-09 V8)

Market Price $319.99 You Save 20% ($64.00)

$255.99 (kit)

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  • Item 100576
  • MPN# 100576

In Stock Ships same business day. Choose options to add to cart

Features & Details

  • Money Saving Combo Kit
  • Ford Racing 3.73 Gears - 8.8"
  • Motive 8.8" Rear End Installation and Bearing Kit
  • 1 Bottle of Ford Racing Friction Modifier
  • 2 Quarts of Royal Purple Max Gear 75w90 Gear Oil
  • Fits 1986-2009 V8 with 8.8" Solid Rear Axle
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, 1 bottle of Friction Modifier, 2 bottles of 75w90 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 Speedometer Gear, 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 1986-2009 GT, Bullitt, Mach 1, Shelby GT500 and 1994-1998 SVT Cobra. It will not fit the 1999-2004 IRS equipped Cobra Mustangs.

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: 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 Details

What's in the Box
  • (1) Ring gear
  • (1) Pinion gear
  • (1) 3.8 fluid oz bottle of Friction Modifier
  • (2) one quart bottle of Royal Purple Max Gear 75w90 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?
  • Foxbody - 86, 87, 88, 89, 90, 91, 92, 93
  • Cobra - 93, 94, 95, 96, 97, 98
  • GT - 94, 95, 96, 97, 98, 99, 00, 01, 02, 03, 04, 05, 06, 07, 08, 09
  • Bullitt - 01, 08, 09
  • Mach 1 - 03, 04
  • GT500 - 07, 08, 09

Most Helpful Reviews

5/5
Nice improvement

The improvement off the line is very nice. I took it to a local shop so I can't say much about the install. But I can say when I got it back I loved the overall power out of the hole I got.

Helpful (1)

5/5
3.73 gears and install kit

Best upgrade so far came with everything needed. Dropped the car off at the shop to get the gears installed picked it up the next day and WOW!! Totally different car it seems like first, second, third, ...

Read More
Helpful (1)

Overall Rating 4.9 out of 5 stars
Read All 74 Reviews

Customer Photos (11) Submit Your Photo

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9 Questions / 10 Answers

Ask a Question

Rear wheel bearings Will this kit include the wheel/axle bearings or do I have to get them separate ?

robert11111

  • The rear wheel bearings and seals are usually separate. They come in a set for about $25-30.

    joetrainer31

    Good Answer (0) (0)

Show 2 more answers Question Resolved

will it fit a v6? Will this fit a 2003 v6 with a 8.8 28 spline axle?

Drakmathal

  • Only if you have an 8.8 rear end already.

    Cole21

    Good Answer (1) (0)

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

does your install kit include a speedometer gear

JCD111

  • The Ford Racing 3.73 Gears and Install Kit (86-09 V8) does not include a speedometer gear. If you were looking to obtain a speedometer gear as well, depending on your year and transmission, check out what we have on our site under Speedometer Gears!

    KevinD92

    Good Answer (0) (0)

Question Resolved

When its hot out andi drive a while I get a rubber squeeling noise when I turn .Is this just soft tires or could there be a problem with my differential?

JCD111

  • There are a lot of factors that could play into a noise like this. I highly recommend having a shop take a look at your car to see what the cause may be.

    SalC7

    Good Answer (0) (0)

Question Resolved

What's the difference between this kit and the one for the 10-14 mustangs? Aren't all GT differentials the same from 05-14?

JeremyJAK

  • There are two differences between the Ford Performance 3.73 Gears and Install Kit (86-09 V8) and the Ford Performance 3.73 Gears and Install Kit (10-14 V8; 11-14 V6) (Item #100573) 86-09 has 75w90 gear oil where 10-14 has 75w140. 10-14 also has Ford Rear Gear Pinion Bearing - 8.8in (10-14 V8; 11-14 V6) (Item #52994) where the 86-09 kit does not.

    JeffAM

    Good Answer (0) (0)

Answer This Question I need this answered (0) (0)

When do you buy the Traction Lok rebuild? I have an 07 GT with 58,000 miles and I am purchasing the 3.73 gears kit, do I need to by the traction Lok rebuild kit?

07beachGT

  • If your not having any problems with your rear end right now it's probably not necessary. Some people like to rebuild it just for safety sake when they change gears but it's not necessary. Plenty of people just change out the gears, me included, with the kit your looking at with no problems. Think of it more as an insurance policy. If you feel you need it go ahead but it's not absolutely necessary.

    Arlander

    Good Answer (4) (0)

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

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Customer Reviews (74) Write a Review

Overall Rating 4.9

out of 5 stars

Installation Time:Weekend

Installation Cost:$250-$500

  • Performance Gain 4.779661 4.8
  • Fit 4.830509 4.8



  • 5/5

    August 04, 2016

    Great kit!

    I had my local Ford service department install it and they were impressed that it included everything needed for a clean installation. The new gears are much quieter than the ones they replaced. Thanks AmericanMuscle! Arizona

    BottleRocket

    Year: 2007 Submodel: GT

    Helpful (1) (0)

  • 5/5

    Installation Time: Full Day

    May 13, 2016

    Love

    Love this set of gears, personally like the oil it comes with. Fast shipping! Thank you Am!

    Brando

    Year: 2001 Submodel: GT

    Helpful (1) (0)

  • 4/5

    Installation Time: Full Day

    March 03, 2016

    great

    It gave my pony just what it needed to unlock it's hidden power!

    StringBean

    Year: 2002 Submodel: GT

    Helpful (1) (0)

  • 5/5

    Installation Time: Shop Install

    March 02, 2016

    Good Price Good Product

    Works real good and I think a Good price for Ford Racing Productions comes with everything you need!

    Banshee006

    Year: 1996 Submodel: Cobra

    Helpful (1) (0)

  • 5/5

    Installation Time: Shop Install

    November 16, 2015

    Aadded 3.73 gear

    This gear was chosen due to the reviews of others , and past experience. I have had mustangs with 4.10 and you don't give up much using a 3.73 but you have a little friendlier drive in 5th gear. Gearing on a stock GT In this year is usually a 2.73 , you can check code on door if it is listed as M under axle that is what you have, this change a lone with make a huge gain in acceleration. You will need to order a 21 tooth white speedometer gear to correct speedometer.

    mustang96

    Year: 1996 Submodel: GT va beach va

    Helpful (1) (0)

  • 5/5

    Installation Time: Shop Install

    Installation Cost: $250-$500

    October 30, 2015

    3.73 gear install

    Well worth the money. Went from a 3.31 to a 3.73. Had a local speed shop install. All around pull is much better. Not realy much of a mileage loss. 80 mph is about 2600 rpm. Much more responsive. Would definately recommend this. It's a must if you only have 3.31's.

    Jsmyer

    Year: 2008 Submodel: GT Lewisburg ohio

    Helpful (1) (0)

  • 5/5

    Installation Time: Full Day

    September 28, 2015

    Not bad

    This is a nice upgrade for little more power! Not to hard to put in at all!! Took a good 7-8hrs to put it in, so worth the time and money!

    mercerjays

    Year: 2004 Submodel: GT Topeka

    Helpful (1) (0)

  • 5/5

    Installation Time: Afternoon

    September 29, 2014

    Added some great get-up and go!

    Recently added these gears to my mustang and it for sure get the mustang off the line a lot quicker. My fuel mileage on the highway has not dropped off to bad as well!

    ForrestS

    Year: 2002 Submodel: GT

    Helpful (1) (0)

  • 5/5

    Installation Time: Weekend

    April 22, 2014

    ford racing 3.73 gears are a MUST!!!

    These gears will wake up your pony and you will notice the difference From the STOCK!!! HURRY and put one in your cart today!!

    Sinistergt94

    Year: 2002 Submodel: GT Cotulla, TX 78014, USA

    Helpful (1) (0)

  • 5/5

    Installation Time: Shop Install

    Installation Cost: $250-$500

    April 22, 2014

    Excellent Products

    I got my gears from Americanmuscle.com and had them installed at a shop and the cars feels amazing and faster, you can feel the difference on the car already. I got everything I needed in this kit. I'm really happy with the product.

    Davino50

    Year: 1994 Submodel: GT Paramount, CA, USA

    Helpful (1) (0)

  • 4/5

    Installation Time: Shop Install

    Installation Cost: $500-$1000

    March 22, 2014

    Good gains

    The product was great priced and a good upgrade, can definitely feel the gains. I would recommend this to anyone. The only negative was how much the shop charged for install. I had to pay $550 which I feel is a little high.

    Rick24

    Year: 1988 Submodel: GT

    Helpful (1) (0)

  • 5/5

    Installation Time: Full Day

    March 21, 2014

    3.73 gears and install kit

    Best upgrade so far came with everything needed. Dropped the car off at the shop to get the gears installed picked it up the next day and WOW!! Totally different car it seems like first, second, third, fourth, fifth all in the perfect RPMS to have a ton of fun! And as always American muscle has the right parts to make your stang come alive!

    Bens197

    Year: 2008 Submodel: GT Winder, GA, USA

    Helpful (1) (0)

  • 5/5

    Installation Time: Shop Install

    Installation Cost: $100-$250

    March 21, 2014

    Nice improvement

    The improvement off the line is very nice. I took it to a local shop so I can't say much about the install. But I can say when I got it back I loved the overall power out of the hole I got.

    tmoez

    Year: 2005 Submodel: GT Charlotte, NC, USA

    Helpful (1) (0)

  • 4/5

    Installation Time: Shop Install

    Installation Cost: $100-$250

    February 21, 2014

    Good product

    Love the way it woke my car up from the factory gear. The only complaint I have is that the shims dont fit 100%. Other then that...great product!

    mystang02

    Year: 2002 Submodel: GT NC

    Helpful (1) (0)

  • 5/5

    Installation Time: Afternoon

    June 02, 2014

    Great acceleration

    I can definitely feel the acceleration when I step on the gas pedal. I had my local shop install the gears for about 270 not to shabby. The only thing is now my speed odometer is off which I need to adjust but overall I recommend this product

    mikes99gt

    Year: 1999 Submodel: GT Anderson, SC, USA

    Helpful (3) (0)

  • 5/5

    Installation Time: Shop Install

    Installation Cost: $100-$250

    April 29, 2014

    Gitty up and go

    The 3.73 gears really gives the Mustang the go that it needed off the line or from a stand still. I could tell the difference that the 3.55 factory gears did for my sons car and wanted more. The 3.73 gears are very street friendly with the overdrive only running 2100-2200 rpm at 65 mph. The wife even could tell how it put her back in the seat more. I did not want the engine to scream because I have Corsa after axle exhaust and a convertible so running quite when needed was important. Great choice without going too far.

    DakotaStang

    Year: 2007 Submodel: GT Box Elder, SD, USA

    Helpful (2) (0)

  • 5/5

    Installation Time: Shop Install

    Installation Cost: $500-$1000

    March 25, 2014

    1998 Cobra

    Gears are a must for any mustang of any year. The stock 98 Cobra gears are 3.27's. You'll hear the debates of 4.10's minimum for the B-Headed 96-98 Cobras, but I disagree. The 3.73's provide a great acceleration, yet first gear is still usable and highway cruising won't get you past 2600rpms (and thats cruising at 80mph). This kit is a great bang for the buck, although I did use different gear oil than the Royal Purple provided because i've heard Royal Purple has gone down hill in the recent years. I also added axle bearings in my order. Couldn't be happier with the purchase.

    gkomo

    Year: 1998 Submodel: Cobra

    Helpful (2) (0)

  • 5/5

    Installation Time: Shop Install

    Installation Cost: $250-$500

    October 12, 2015

    Makes the stang way more fun to drive!

    Installed on a 03 mustang gt. Already had a tuner so adjusting the speedometer wasn't a problem. Still in the break in period but so far its a nice upgrade to the gearing of the car. No more underpowered sluggish feeling in 5th gear cruising. Can really feel the quickness off the line and through the gears. The tires can be broken loose with ease. The mechanic had mentioned that the rear needed 3 bottles of gear oil. Not sure why there are only 2 bottles included in the kit but thats no big deal. Overall If I ever own another mustang this will be the first mod to be done before any intake or engine work.

    J

    Year: 2003 Submodel: GT New Jersey

    Helpful (1) (0)

  • 4/5

    Installation Time: Full Day

    April 22, 2014

    3.73 Gear kit

    The kit is great and gives a good performance upgrade. The only small problem was I could not get the crush sleeve to crush and ended up using the old one. I highly recommend this product.

    swilson84

    Year: 2005 Submodel: Cobra North Carolina, USA

    Helpful (1) (0)

  • 5/5

    Installation Time: Afternoon

    March 25, 2014

    Feels like Horsepower

    Great product! These gears really wake up a Mustang. As a stand alone mod these gears will make your 'Stang feel like it is making significantly more power. Low end pull is awesome. Highway rpm's are a little higher than with stock gears, resulting in slightly less gas mileage, but well worth the trade. Great "seat of the pants" improvement.

    Marc03GT

    Year: 2003 Submodel: GT Upstate, New York

    Helpful (1) (0)

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