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Ford Performance Ring Gear and Pinion Kit - 3.73 Gears (05-09 GT)

Market Price $179.99 You Save 6% ($10.00)
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$169.99

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  • Item 24001G05
  • MPN# M-4209-88373

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    Features, Video & Details

    • Ford Racing Quality
    • Strong Forged Construction
    • 3.73 Gear Ratio
    • 8.8" Ring Gear Diameter
    • For Street or Track Use
    • Fits 2005-2009 GT, Bullitt and GT500 Mustangs

    Review & Installation Video

    Review & Install Video

    Hey, guys, Stephanie with AmericanMuscle.com here with these Ford Racing 3.73 gears for all Mustangs with an 8.8 rear or '86-'14 V8 and 2011-2014 V6 Mustangs. Gearing's really important to a car, and it can make or break a build no matter how much power you may or may not have. Gears should be carefully chosen based off your intentions and the performance that you want out of your car. These 3.73 gears from Ford Racing are gonna be a good option for those of you out there that aren't wanting to spend a ton of money, but that are looking for a good gear that will perform well for a daily driver and for the car that might see the track occasionally. I would say that the 3.73 gear is a middle of the road option. It's short enough to provide a huge difference in driveability, but not so short that it'll create a negative impact on street driving. When you go about choosing your rear gear, you'll have to keep in mind where and how you mostly drive your car. You do a lot of highway driving, you aren't going to want a short gear, and if you're looking for acceleration improvements from a stop, you aren't going to want a tall gear, either. A 3.73 gives you a little bit of both worlds here. You'll get a cruise on the highway without screaming in those higher RPMs, but you're really going to notice a big change in acceleration as well and that's what makes these good for a daily driver. If you're coming off of stock gearing and you're moving into a 3.73, you're going to think that you're driving a totally different car because the gears are gonna totally change the driving experience. Even if you have some bolt-on mods already, your car probably still feels sluggish but it won't after the gears are installed. If we break this down some, the basic way that rear gears work can be boiled down to saying that the number of the gear is how many times the drive shaft will turn to one turn of the rear wheels. So in this case, the drive shaft will turn 3.73 times for every one turn of the rear wheels, and this is how such drastic changes in the driving experience are made. Typically speaking, low gears give higher top speeds and better fuel economy, but the tradeoff there is a car that's slower off the line with less torque. High gears, on the other hand, are the exact opposite and the 3.73s hear fall in the middle, and they're a great all-purpose type of gear. A set of gears includes a ring and pinion gear and Ford Racing gears a forged gear that are CNC cut with lapped gear teeth. These also have a black oxide finish, so that'll help resist corrosion, and in case you happen to be worried about it, these are not a noisy gear so don't expect a lot of whine with these. Upgrading rear gears will throw off the calibration of your speedo no matter which brand you end up choosing. It's just a side effect of choosing the ratio, but Ford Racing does make a recalibration tool to fix this issue, so just keep that in the back of your mind. Or the issue can be fixed with a tuner, as well, but if you don't happen to already have a tuning device, then the recalibration tool is going to be a less expensive way to fix it. As far as price, these gears are going to be the least expensive that are available on the site, costing under $150. There are some other brands to choose from but they're gonna be more expensive, and I did want to mention that you should also pick up a gear install kit while you're purchasing these. The price of this kit is going to change depending on if you want just the install kit or an install and bearing kit, but you're looking at an additional 30-75 bucks for either one of these. And depending on the mileage and the last service, it could also be a really good idea to invest in entirely rebuilding the rear while it's apart, but that's up to you. So I'm not gonna say that the install here is easy because it's not. You're looking at taking the car to a shop for a proper install or having a nice collection of tools since you will need a handful of items and about four hours to get the job done yourself. This is a three out of three wrenches on the difficulty meter. This is a pretty big project that's going to require removing the axles, which means dropping the driveshaft, the rear brakes, the diff pinion shaft, and the axle shaft U-washer, and you've got to remove the differential itself, which means removing the diff bearing cap bolts and the shims, which all needs to be marked and reinstalled the same way. The assembly and install of the new gears is very specific, and I'm obviously giving you guys a general overview here, so I'll just mention that you'll need to check for diff case run out as well as check pinion depth and do some shimming, as well. Then you've got to get it all back together after measuring and checking your work over. Wrapping things up here, the Ford Racing 3.73 Gears for the 8.8 rears are a great gear for cars that see a lot of street time and some track time. They're a middle of the road gear that offers the best of both worlds when we look at the benefits of a tall gear versus short gear, and they're the most affordable gear set on the site. They are CNC cut and they have lapped teeth, and you can check them out more online right here at AmericanMuscle.com.

    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. Ford Racing Ring and Pinion Gears are perfect for street, road, or race use.

    Superior Quality. These Ford Racing 3.73 Mustang ring and pinion gears feature a super strong forged construction, CNC cut & lapped gear teeth, and a black oxide finish to resist corrosion.

    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 Ford Racing Ring and Pinion Gear set will fit all 2005 to 2010 V8 Mustangs including the GT, Bullitt and GT500 models. A master bearing kit is recommended by most installers, especially on high mileage vehicles, see drop down option above.

    Attention 2010 and newer Mustang Owners. Starting in 2010 Ford changed the inner rear gear pinion bearing in all 8.8" equipped Mustangs. Because of this you will require a new 8.8" rear gear pinion bearing (Ford part# 9L3Z-4630-A) for proper installation, please see drop down option above.

    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: 2005 2006 2007 2008 2009 Details

    CA Residents: Warning: California's Proposition 65

    What's in the Box
    • (1) Ring gear
    • (1) Pinion gear
    Installation Info
    Tech Specs

    Approximate RPM for 2005-2010 GT


    Manual
    Gear @25 MPH @35 MPH @45 MPH @55 MPH @65 MPH @75 MPH
    1 3888 5443 6998      
    2 2301 3221 4141 5061 5981 6902
    3 1518 2126 2733 3340 3948 4555
    4 1150 1610 2070 2531 2991 3451
    5 782 1095 1408 1721 2034 2347


    Automatic
    Gear @25 MPH @35 MPH @45 MPH @55 MPH @65 MPH @75 MPH
    1 3704 5185 6667      
    2 2634 3688 4741 5795 6849  
    3 1771 2480 3189 3897 4606 5314
    4 1150 1610 2070 2531 2991 3451
    5 817 1143 1470 1797 2123 2450
    Will it fit my Mustang?

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    Questions & Answers (12)

    5 Top Rated Questions

    I have an 07 GT with some bolt on's, Roush CAI tuned to 93 octane. I have 3.31 gears and looking at going 3.73. Just looking for a bit more off the line if ever needed :) but didn't want to kill top end or gas mileage. Thought that would be a middle of the road option. I see that there is a recalibration needed to correct the speedometer. I am using the Diablo tuner. I know when I program the car it asks for the gear. If I retune it and select the same but enter the 3.73 gears, would that calibrate it? Didn't want to buy the calibration tool if I didn't need to. Thanks for any input.

    • When installing your Ford Performance Ring Gear and Pinion Kit, selecting the gearing as 3.73 will correct the speedometer in your 2007 Mustang GT.

    Helpful (2)

    if i have my local ford dealer install these can they calibrate my speedometer?

    • I would suggest calling your local Ford dealer to check and see if they will install the Ford Performance 3.73 Gears and if they can calibrate your speedometer as well although I do not believe they can recalibrate the stock tune for larger gears. I suggest using the Ford Performance Speedometer Recalibration Tool ( which can be found here: https://www.americanmuscle.com/ford-speedo-tool-9410.html ) to properly recalibrate your speedometer after you get the 3.73 gears installed.

    Helpful (1)

    I have a 2007 Mustang GT completely stock and this will be the first mod I will be applying to it. I know I will need a bearing kit. What else may I need to install this part and is there anything else that I will need to upgrade or purchase along with the new gears?

    • We would suggest purchasing the items under the "Buy Together " tab. Those are all parts you are going to want to replace. Especially on Mustangs older than 4-5 years.  

    Helpful (0)

    I have 3.55 in my 07 GT, but the rear end has went out for the second time in about a months time. The first time we replaced the pinion bearing and reoiled and it worked but with a whine. It blew again on the highway :/. My question is, if I get these will they have to be shimmed or anything or would I be good to just tear down and swap?

    • The Ford Performance Ring Gear and Pinion Kit and all other gears we offer will require proper shimming in order to achieve the correct gear mesh pattern.

    Helpful (0)

    If I have a Baja hand held tuner, will they be able to send me the correct tune to fix my speedometer?

    • Bama can create new tune files to correct the speedometer for the Ford Performance Ring Gear and Pinion Kit.

    Helpful (0)
    Post Your Question
    7 More Questions
    So I've heard both ways. You get gears, you NEED a tune. You get gears, tune isn't necessary. I would like to buy these gears and get them installed. But do I really NEED to tune it afterwards? And if I don't, what are the consequences? Please if y'all could help me out. 1 answer
    Is a tuner necessary to correct the Speedo after gears or can a dyno shop correct the speedo without a tuner? 1 answer
    Hello guys, I recently had this set of gears installed and I've completed my break in period so now its time for the gear oil change. I am wondering it if would be best to go with 75w140 oil which is what the stock gears used on the 08 Stang. I know the gears come with 75w90 but ford had a TSB where they changed all there oil to 75w140 due to complaints of rear end noises. 1 answer
    i want to go without a tune or recalibration tool would that work out or would it effect my engine ? and can i go only for the gears and get the other parts later ? 1 answer
    What gains will I notice in my 07gt500? I know the KR and super snake came with a 3.73. What will I notice changing from a 3.31? I have an 07 gt500. I realize it came with a stock 3.31. I know the gt500KR and the Super Snake came out with 3.73. What awe the advantages of the change? 5 answers
    Will a Gear upgrade need a tune? Thinking about giving my automatic 06GT a gear upgrade. Will this require a re-tune of any sort? Bama, Diablo, etc.. Thanks! 4 answers
    how noticeable are 3.73 I have a 2007 GT and I know that the stock gear ratio is 3.55. My question is how noticeable would a change to 3.73s be because it doesn't seem like the significant of a change 4 answers

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    Customer Reviews (74) Write a Review

    Overall Rating 4.8

    out of 5 stars

    Installation Time:Weekend

    Installation Cost:$250-$500

    • Performance Gain 4.75 4.8
    • Fit 4.833333 4.8



    • 4/5

      Installation Time: Shop Install

      Installation Cost: $250-$500

      September 03, 2018

      Great gears

      3.73 gears are a huge improvement over the stock 3.31s. Ford raceing gears need to be toured down to 100 vice 85 pounds on stock gears. Also put in the carbine fiber clutch pack and sytehnenic oil. Cruise 75-85 on the freeway at 2500-2750 rpms in 5th gear. Can grab 3rd gear at 80mph and pulls pretty hard up to 145mph. 1st gear pulls hard to 35mph and chirps 2nd on 255/50r18 Firestones. Wanted to get the 4.10s but they were on backorder. All in all I am satisfied with en but wonder how the 4.10s would be. Probably upgrade to 4.10s next summer on 295/45r18 nitto555 g2s.

      BenjaminA

      Year: 2009 Submodel: GT

      Helpful (0)

    • 5/5

      Installation Time: Afternoon

      August 27, 2018

      Nice extra Bite

      Had 3.55s but these added extra grab going into higher gears! With carbon discs

      BrandonGTboy

      Year: 2011 Submodel: GT

      Helpful (1)

    • 5/5

      Installation Time: Shop Install

      July 23, 2018

      Ford Performance Gears 3.73

      A big change in the performance of my Mustang. I am very pleased with the results. Only about 200 RPM's more at highway speeds.

      JohnP

      Year: 2007 Submodel: GT

      Helpful (2)

    • 3/5

      Installation Time: Full Day

      June 30, 2018

      feel the different

      increases acceleration needs addtional service parts for 8.8 rear axle

      Arthur

      Year: 2005 Submodel: GT

      Helpful (1)

    • 5/5

      Installation Time: Shop Install

      Installation Cost: $250-$500

      March 16, 2018

      3.31 to 3.73 upgrade

      I had the new gear installed professionally. I have 500 miles for break in. I had to adjust the computer it was 3 mph off. I used my tuner. I have noticed running 60 mph I am running about 2 grand versus the normal 1800. So far what little I have drove it, no major change in fuel. It might end up being a mpg or two different. I can't do a good pull on it jet but so far it feels and sounds good. Can't wait to see the difference. I hear good things.

      Bluethunder287

      Year: 2007 Submodel: GT

      Helpful (3)

    • 4/5

      Installation Time: Afternoon

      Installation Cost: 0-$100

      March 14, 2018

      Solid Gears

      Got mine installed by a mechanic I know. Gears are silent as they should be. Great matchup for 2-5th. With the TR3650 its a little too slow of a gear for 1st. You basically shift out of 1st right off the bat unless you rev it out over 3000. I would not go any more aggressive than this for a street car because you'll find yourself shifting a lot. Mileage on the highway is not too bad. 80 mph yields just a hair under 2500rpm and 27-28mpg. My car is has hot rod cams, long tube headers, and a Paxton 1200SL non intercooled. ~8psi ~490-500whp on 91 octane

      StangManForever2008

      Year: 2008 Submodel: GT

      Helpful (10)

    • 5/5

      January 30, 2018

      great mod

      noticed big difference in acceleration as soon as you pull from the light,havent stomped on it yet,waiting for break in

      HurriahB

      Year: 2006 Submodel: GT

      Helpful (4)

    • 5/5

      Installation Time: Shop Install

      Installation Cost: $250-$500

      January 27, 2018

      Very happy w/the FRPP 3.73's!!

      I had OEM 3.73's on my former '08 Bullitt and loved them because they moved the powerband down low- lots better bottom end and quicker acceleration. My '14 GT Track Pack also came w/OEM 3.73's and loved them on that car for the same reason. IMHO, the OEM 3.31's on my '09 GT500 made the bottom end feel soft. The 'experts' cautioned me against 3.73's, citing that the KR model of the GT500 had 3.73's because of the larger wheel size to which I said, 'bunk.' I was also warned about the MPG issue, which I chuckled at. The increase in bottom end and roll-on power was immediate and significant and my MPG has actually gone up. The theory goes that your gas mileage will be grossly affected by 3.73's. Well, my Bullitt averaged 24-27 highway MPG, my '14 GT T/P was well over 22 highway MPG and I've actually noticed an INCREASE in highway MPG since the 3.73 gears were installed on the GT500. I'm guessing the engine is now sitting in the 'sweet spot,' especially during my daily commute, where the engine is running at near optimal performance. I've seen 25 MPG on some occasions but generally, the MPG has been up 2-3 MPG on the highway. I use to have to fill up every 2-3 days and now I'm getting at 4-5 days out of every tank. 3.73's are a win-win to me. I will caution buyers to NOT buy used 3.73's. Sadly, that was a lesson I learned that cost me time and $$. The used gears looked perfect, brandy new even, yet once installed, they could not be properly aligned and the dreaded whine was ever-present. I'd never buy used gears again, don't care how pretty they look. Spend the extra $$ and get new FRPP gears, as well as the proper type/amount of oil and ring/pinion installation kit. Lastly, and perhaps most importantly, make sure the shop you bring it to knows what it's doing. Nothing worse than listening to whining gears that were installed improperly.

      spectreman

      Year: 2009 Submodel: GT500

      Helpful (4)

    • 5/5

      Installation Time: Shop Install

      Installation Cost: $100-$250

      December 18, 2017

      It is what is Is.

      Good Fit. No complaints. Good Install by Dan the Man!

      GregM

      Year: 2006 Submodel: GT

      Helpful (3)

    • 3/5

      Installation Time: Afternoon

      November 20, 2017

      Ok quality.

      Picked up the ring and pinion at American Muscle which is really nice. Unfortunately, they required a lot of deburring and the fit wasn't as easy as I hoped. Finally got them within spec, but after breaking them in they were trash. The pattern wasn't where they should be and as a result I found a set of factory installed 3.73's which worked straight away and have been trouble free from the get go.

      Cup

      Year: 2008 Submodel: GT

      Helpful (3)

    • 5/5

      September 15, 2017

      Great mod

      Great seat of the pants feel! Car pulls harder off the line and when it kicks down to pass. Originally had 3.31 gears. These are super quiet, no noise at all.

      Sally

      Year: 2005 Submodel: GT

      Helpful (3)

    • 5/5

      Installation Time: Afternoon

      April 03, 2017

      Only thin I USE

      Ford Performance gears are all we try to use in my shop,we Install lots of Ring and pinions ,Ford is the best for the 8.8 and 7.5 Rears .not saying you cant get a bad set but its not often that happens.Ford Is on top of there game right now.If you want a wine buy Richmond or motive there good for that.

      Flipper

      Year: 2001 Submodel: GT

      Helpful (3)

    • 5/5

      Installation Time: Afternoon

      November 27, 2016

      Always a great upgrade!!!

      Have owned 48 mustangs in my time and one of the best upgrades is different gears in the rear!

      Trigr1

      Year: 2007 Submodel: GT500

      Helpful (3)

    • 5/5

      August 22, 2016

      I love it

      WOW.this Gear 3.7 makes my car run soooo fast. I can feel the change on the road and racing as well

      Rubu

      Year: 2007 Submodel: GT

      Helpful (3)

    • 3/5

      August 03, 2016

      Quality parts, speedy delivery.

      My rear end came apart in me one day, a couple of years after my supercharger install. This part was the fix to all my problems. The gear change combined with my LSD puts a constant smile on my face with all the tire burn out marks on the road. The neighbors absolutely hate me now.

      Redhorse

      Year: 2005 Submodel: V6

      Helpful (4)

    • 5/5

      Installation Time: Afternoon

      July 05, 2016

      Really helps off the line and ETs

      I installed these along with my BBK Long Tube Headers and my 1/4 improved quite a bit. If you're thinking about doing gears, you won't go wrong with these FRPP 3.73s!

      RedS197

      Year: 2006 Submodel: GT

      Helpful (3)

    • 5/5

      Installation Time: Shop Install

      Installation Cost: $250-$500

      May 20, 2016

      05 Saleen 5 spd

      This is perfect gear for 5 spd car. 80MPH is 2500 RPM. Makes driving a lot more fun and responsive.

      Ammotroop

      Year: 2005 Submodel: Other

      Helpful (3)

    • 5/5

      Installation Time: Weekend

      March 02, 2016

      High quality silent gears!

      This is my third gear set and the first that has been absolutely silent and I have poly/rotojoint upper and lower control arms/panhard that transmit every noise that they possibly can. After two shop installs I finally bought the tools to do this myself and it was completely worth it. I lived with a noisy gear set for way too long and finally after much research did this myself after something came apart from the last install. Upon disassembly I found parts of a broken cast iron stock differential shim that was causing all sorts of vibration and noise. If you have ultimate patience and mechanical understanding, this job is not terribly hard but a thousandth of an inch is the difference between quiet and whiney. Make sure you have other transportation because you do not want to rush this job while the car is down. A set up bearing saves a lot of time trying different pinion shims, the old was a .024 and I ended up with a .030" to get the correct pattern with 9 thousandth average backlash for zero noise and zero clunk.

      Panamactd

      Year: 2009 Submodel: GT

      Helpful (3)

    • 5/5

      Installation Time: Afternoon

      August 28, 2015

      Good with the gears

      Got a great deal on the gearset. I work at a Ford dealer so installed them in a few hours. Nice and quiet, and a perfect gear ratio for my stang! I ended up getting a tuner to take advantage of the gears and set the speedo back to accurate.

      Thegrubeguy

      Year: 2007 Submodel: GT Tempe, AZ

      Helpful (3)

    • 5/5

      July 03, 2014

      these gears should be OE

      Im very happy wish i did this mod first no complaints at all evan hiway driving is a pleasure.The only bad thing I can say is that I mash the pedal constantaly.

      dave285

      Year: 2007 Submodel: GT Kingston Pa

      Helpful (4)

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