Full Floating 9" Rear End System - 13" rotors, '4R' 4 piston radial mount calipers with parking brake

Score: 5.00 (votes: 1)
Reviews: 1
  • $5249.00

Our Full Floating 9" Rear End System eliminates pad knock back and removes the safety concern of breaking an axle.

This Full Floating rear end features 13" rotors and a parking brake. Fits 17" wheels. 


Introducing our revolutionary

 Full Floating 9" Rear End System

This system features:
13"x1.1" rotors, '4R' 4 piston forged aluminum radial mount calipers & a parking brake.  Fits 17" wheels or larger.  Available for leaf springs or our 3-Link rear suspension system. 


When building a maximum performance street or track car you find all sorts of weaknesses in the stock components.  One major component that desperately needs attention is the stock rear end.  Its semi-floating design allows the axles to move back and forth slightly on square roller bearings.  If you want to run serious rear brakes in the form of a fixed caliper, you'll find this movement pushes the pads away from the rotor when cornering, only to really get your attention when you need to brake for the next corner.  You end up pumping the pedal or have a very long pedal as you have to move the pads back to the rotor face before any friction can occur and slow the car.  Not an enjoyable feeling.  A much more preferable situation is a pedal that is in the same position every time and having amazing stopping ability each and every time you step on the brake pedal.  Brakes are not optional!


One other major safety concern with the stock rear end housing and axle design is that if you break an axle in the right spot, you can loose a wheel!  Think about it.  All that holds your wheel on is the flimsy stock bearing retaining plate and the bearing being pressed onto the axle.  If the axle breaks on the outboard side of the bearing or the bearing fails the wheel is able to fly off in a direction you don't really want it to go!  With today's sticky tires and modern suspension designs exerting way more loads onto components that were originally designed for skinny bias ply tires, we should all take a long hard look at these critical safety areas of our cars.

Our Full Floating 9" Rear End System eliminates pad knock back and removes the safety concern of breaking an axle.  The weight of the car now rides on the housing, not the axle like the stock design. 

"The ULTIMATE rear end for your Hot Street, Pro Touring, Drag or Road Racing car"

Click on any of the images below for a larger version.

Trailing arm brackets and Watts Link brackets come pre-installed.  You can also see the flange that the parking brake mechanism bolts to.
Here you can see the parking brake mechanism bolted to the axle tube flange.  You can also see one of the massive inner tapered roller bearings.
Our USA made rotor is bolted to the iron rotor 'drum' hat.  The hub is installed along with drive plate, dust cap and bullet nosed ARP wheel studs. ('4S' calipers shown for reference).
Our forged aluminum 4 piston caliper is shown installed with our CNC machined billet steel mounting bracket.   ('4S' calipers shown for reference).


 Housing features a fill, level and drain plug.  These can also be used to plumb a rear end cooler.
 7/16" stud is welded to the top of the drivers side axle tube. Picture shows our intermediate brake hose ready to be secured with a nut (hose not included).
 Baffled -6AN vent fitting allows for easy and convenient vent hose connection. 

Watch as we install the hub, rotor & caliper onto our Non-Parking Brake Full Floater


Click the link below to see what Mustangs Monthly had to say about our Full Floating rear end


  Our Full Floating 9" Rear End System includes:
  • Brand new, heavy duty 9" housing with full 3" O.D. axle tubes.  Brake brackets, leaf spring saddles, Watts Link and/or trailing arm brackets come installed and are beautifully and professionally Tig welded, then the housing is straightened to ensure trueness.  Housing is powder coated gloss black and looks almost too nice to install out of sight under your car!
  • Housing includes a baffled -6AN vent tube on the LH side, fill, level and drain plugs and a 7/6" stud on the LH axle tube for brake flex line mounting.
  • Solid premium alloy steel, double heat treated, 31 spline, fully polished axles.  Axle installation and removal tool included.
  • Axle tube seals.  These install in the housing to keep gear lube from migrating down the tubes and keep it in the center section of the housing.
  • Forged 4140, heat treated steel hubs with races pre-installed.
  • Heat treated drive plates.
  • Drum in hat parking brake mechanism's and universal fit cable set included.
  • 3" long 1/2-20 ARP bullet nose wheel studs pre-installed into hubs.
  • Massive tapered roller bearings, keyed washer, nut and lock ring.  Special spindle nut socket included.
  • 13" x 1.1" heavy duty rotors mounted to aluminum parking brake hats.  Packages under most 17" wheels without wheel spacers. 
  • 4 piston stress flow forged radial mount aluminum calipers & pads.  Each caliper is equipped with stainless steel bridge plates. The plates eliminate the bridge wear caused by pad gouging and extend the service life of the caliper body. The spring-loading action of the plates also eliminates pad rattle and dampens the vibration harmonics that contribute to squeal under braking. Other features include high temperature seals and stainless steel pistons to eliminate corrosion and retard heat transfer from the pads. Internal fluid passages eliminate the need for external tubes. Four corner bleed screws assure simple and effective air evacuation.  Calipers come standard powder coated either bright red or gloss black. The most noteworthy feature of these calipers is the exceptional strength and reduced weight of the forging. With assembled weights just at 4.4 pounds, the caliper body design in itself is a product of computer generated solid modeling and stress analysis technology. Each caliper features closed end bridges with a radial transition down to the main body and piston bore housings. The elimination of machined steps and sharp shoulders in this critical area provides a measurable increase in overall body strength and resistance to deflection under load. Every caliper body is stress-flow forged from a premium grade aluminum alloy billet.
 Specialized spindle nut socket included.

 Axle installation/removal tool included.

 Inner axle tube seals included.


Critical dimensions you should know about our housing:

  • Available in 59.25" wide for 67-70 and 61.25" for 71-73 Mustangs only.  Measured from wheel mounting surface to wheel mounting surface. This measurement is taken from the drum or disk face your wheel mounts to.  If you need it wider please contact us.  Please note that custom ordered housings are non-returnable. 
  • Leaf spring pads are installed 43" on center which is the stock location for 65-70 Mustangs.  If you need them in a different location, please contact us.
  • Leaf spring pad to pinion angle is 3 degrees up.  If you need a different angle please let us know.
  • Also available ready for our 3-Link rear suspension.  Mounts are fixtured and tig welded into position making the rear suspension install extremely easy. 
  • For mini-tubbed cars with inner wheel arches moved to the stock frame rails we will install the trailing arm/shock mounts at 40" on center.  If you move the frame rail over also we will install the mounts at 38" on center.  With either of these you will need to use the Frame Rail mounted trailing arm option with our 3-Link.
  • Pinion is located 3/16" to passenger side which is standard for 65-70 Mustangs.  If you need it offset one side or the other please let us know.
  • A 7/16" x 1-1/4" long stud is welded onto the top of the drivers side axle tube 17" in from the wheel mounting face to enable easy mounting of brake line blocks (please see picture above).
  • A -6AN vent tube is welded on the drivers side of the housing (please see picture above).
  • Standard hubs use the Ford 5x4.5" bolt pattern.  Other bolt patterns are available.
  • Please note that if you decide to change any of our standard dimensions the housing is considered custom and is non-returnable.  Please measure twice and order once.

System is shipped ready to install.  Simply pack the wheel bearings, install the hubs, run brake lines, add your center section, install the axles, fill with fluid and its ready to run!  Our housing is highly customizable and can be made wider/narrower, shipped with or without leaf spring saddles, painted or bare.  If you have a custom application let us know and we will try our best to accommodate you!  All systems are built to order, please allow approximately 6-8 weeks build time.

Customer reviews
Average rating:
5.00 (Votes: 1)
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  • Eduardo
    Everything looks and fits great. The instructions are very detailed and if I did have a question, Shaun would respond with the answer almost immediately.
    I wouldn't hesitate to purchase this rear end again on the next build.
    Street or Track LLC
    Feb 16, 2022, 07:19

    Thank you for your business! This system truly is a work of art and we are proud to produce it.

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