Mustang Parts › Mustang Drivetrain › Mustang Gears › Richmond Performance 3.90 Gears (86-12 V8; 11-12 V6) // Richmond F88389

Richmond Performance 3.90 Gears (86-12 V8; 11-12 V6)

Richmond Performance 3.90 Gears (86-12 V8; 11-12 V6)

About Richmond

Richmond Mustang Performance Gears
Richmond Gear is the leading manufacturer of professional quality, hi-performance ring and pinion sets and transmissions. For over 80 years, the DOUBLE DIAMOND has signified ...... READ MORE

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Rear End Installation and Bearing Kit - 8.8in (86-12 V8; 11-12 V6) - Motive Gears R8.8RMK
Rear End Installation and Bearing Kit - 8.8in (86-12 V8; 11-12 V6)
Our Price $74.99
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OUR PRICE$159.99
Market Price $179.99You Save 11% ($20.00)
Item # 21527
Ships the same business day

Accessories Options

Add Gear Install Kit

Accessories Options

Add Traction-LOK Rebuild Kit w/ Carbon Discs

Accessories Options

Add 8.8in Rear Gear Pinion Bearing

Accessories Options

Add Ford Racing Speedcal
PRICE WITH OPTIONS $159.99
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Product Features

  • Better than OEM quality
  • 3.90 Gear Ratio
  • 8.8" Ring Gear Diameter
  • Fits 1986-2012 V8 and 2011-2012 V6
  • Made in the USA
Improves Off The Line Bite. Are you looking to install a steeper set of gears in your Pony to get more low end grunt off the line? Then look no further than a set of Richmond gears. Richmond has been making high quality gears at a friendly price for well over 80 years.

Made in the USA. Manufactured right here in the USA, Richmond uses state-of-the-art manufacturing and extensive testing to produce a superior quality ring and pinion gear set at an excellent price.

Application. This Richmond Ring and Pinion Gear set will fit all 1986 to 2012 V8 Mustangs including GT, Bullitt, Mach 1, Cobra and the 2012 V6 Mustangs equipped with the 8.8" rear end. 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.

Installation & Tech
Differential Gears - Installation Instructions! Differential Gears - Installation Instructions! Mustang Rear Gears - Tech Article Mustang Rear Gears - Tech Article


Mustang 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, 2010, 2011, 2012 Details >>

Installation Time:

(approx) 4 Hours

Difficulty Level:

Mechanical expertise or professional installation required.

Customer Submitted Installation Guides:

Differential Gears - Installation Instructions
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Fitment:
  • V6 11, 12
  • GT 94, 95, 96, 97, 98, 99, 00, 01, 02, 03, 04, 05, 06, 07, 08, 09, 10, 11, 12
  • Cobra 94, 95, 96, 97, 98, 99, 00, 01, 02, 03, 04
  • Mach 1 03, 04
  • GT500 07, 08, 09, 10, 11, 12
  • Bullitt 01, 08, 09
  • Foxbody 86, 87, 88, 89, 90, 91, 92, 93
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Known Exceptions:
Fits Mustangs equipped with a 8.8" rear end.

Customer Reviews

3.34
  • 5/5
    HUGE improvement!
    December 11, 2010
    Steel_Venom
    1995GTDaily Driver
    Bought this as part of a complete rear-end rebuild on a 1995 GT. These gears make a HUGE difference over the stock 2.73 gears. You it makes the car take off so much faster. Good compromise between 3.73 and 4.10's. With an Auto trans the car cruises at between 2800-3000 RPMs going 60-70mph. Only lost about 2-3mpg as well. Only complaint about this is I can't find a speedometer gear for 3.90 gears anywhere. I see other people are mentioning a gear noise but I don't hear it...course my 'stang is rather loud...
    3 of 3 voted this as helpful.Yes, I recommend this product.
  • 1/5
    noisy
    January 9, 2010
    chris s
    Good ratio...VERY NOISY at cruise...and yes it is set up right ..pattern was perfect......replacing with FORD Gears....also Motive Kit for 8.8 did not include any small shims....only 14's and 30's.
    1 of 2 voted this as helpful.No, I do not recommend this product.
  • 3/5
    Richmond Gears 3.90
    October 14, 2010
    Bill Henry
    1990Daily Driver
    The 3.90 gears really improve your acceleration and are the cheapest way to go faster without sacrificing too much fuel mileage/drivability. I was impressed by the quickness in which my order was received to my front door. However, after installing my 3.90 gears (making sure that both the pinion depth and backlash were correct) I noticed a whine. The whine did not subside after the break in period. I contacted AM who was very helpful and was instructed to speak with Richmond. Richmond did not really do anything to help me and hopefully the gears hold up. So far noise is the only problem. If I could do it again I would purchase Ford Racing gears.
    5 of 6 voted this as helpful.No, I do not recommend this product.