In addition to building in extra camber, there's also the added benefit of reducing brake knock back. Brake knock back is when the axleshaft flexes or moves under cornering and the axle movement then pushes the brake pads outward, moving the brake caliper pistons into the caliper. When you come to the next corner and hit the brakes, there's nothing there for a brief second or two, but depending on your speed into the corner, that can be enough time to put you off track or worse. While knock back is more prevalent in C-clip-style axles, it can occur in 8- and 9-inch rearends when the axleshafts become weak over time, often from the axleshaft supporting the load. In the case of a full floater, the brake package is fixed to the hub, so there is no movement.
For a competitive road race car, knock back can be costly over the course of an event, and while we won't be competing for any road racing championships with our project Mustang, we certainly don't want any braking surprises during a high-performance driving event or similar outing.
Speedway Engineering's full-floating 9-inch axle assembly consists of a custom-made axle housing designed specifically for full-floating axles. The axle's center section is CNC-machined to ensure concentricity at each of the bearing bores to reduce or eliminate stress issues. At each end are extended-length snouts, which prevent tube crush and provide good bearing/hub support. Under the close supervision of Frank Ferrell, Welding Manager at Speedway Engineering, these handcrafted housings and components are precision manufactured at the company's Sylmar, California, facility for your specific application, and based on information you provide.
8a The snouts have been checked...
8a The snouts have been checked for runout and are welded 360 degrees by Juan Alaniz of Speedway Engineering.
8b Check out the precision...
8b Check out the precision fit and superb welding.
9 The axle tubes are fitted...
9 The axle tubes are fitted to the center section and checked for proper depth. Note the dummy third member, which is utilized much like a torque plate is when you hone a cylinder block. The dummy third member simulates the stresses of an installed third member for precision assembly and welding so center section and axle tubes conform.
Is A Full-Floater For You?
We have to admit, this is the first time we've ever been presented with the opportunity to install a full-floating axle in a Mustang. What this has meant for us is the chance to learn something about race-ready axle technology. The beauty of a full-floating 9-inch Ford is its industrial strength demeanor--engineering that takes Ford's bulletproof rearend to a new level. Full-floating technology isn't for everyone and it can get expensive. For durability, easy service, flexibility, and the ultimate form of load distribution as we know it today, Speedway Engineering has the goods for brute street and racing performance.
Build any 9-inch housing you desire because there are four to choose from--Super Light NASCAR Style, Short NASCAR Style, Saturday Night Late Model, and the vintage Ford rounded 9-inch (1957-1966). Choice depends on how you're going to use your Speedway Engineering housing. With the exception being the rounded back, it's challenging to tell the difference, but important to know about when you order.
10 The axle tubes are welded...
10 The axle tubes are welded to the center section with the dummy third member bolted in place. Welding is performed at a conservative speed and heat to prevent distortion.
11 These bungs, fittings,...
11 These bungs, fittings, and vent are welded to your Speedway center section and can be used or plugged depending upon your application. You may also suggest deleting them as necessary except for the vent. However, it's suggested you keep them all in case of setup changes later on.
12 As we're using a torque...
12 As we're using a torque arm rear suspension package from Total Cost Involved, the Panhard bar, sway bar, control arm, and torque arm brackets will be precision fitted and welded to the housing per TCI's instructions.
Float For Your Hard-Earned Buck...
- CNC machining throughout
- Cooler, vent, and drain fittings
- 3.0-inch diameter 0.250-inch wall axle tubes
- V-notched welded seams
- Laser cut truck arm pads and brake brackets
- Longer end snouts
- ARP housing studs
- Every housing guaranteed plus or minus 0.003-inch toe and 0.03-degree camber
- Complete assemblies are shipped with specification sheets that include camber, toe, width, pinion offset, and angle
- Complete assemblies include housing, hubs, hub bearings, seals, nuts, drive plates, dust caps, O-rings, and axles
- Wheel studs
- Trailing arm mounts are located to fit the most popular frames
- Each assembly is made to order though there are popular types in stock
- Choose Your Center Section
13 Each housing is pressure...
13 Each housing is pressure tested to 20 psi to confirm leak integrity. Rear axles rarely see any more than 7-10 psi from normal heat issues. Because they are vented, pressure is virtually never an issue.
14 The axle housing is set...
14 The axle housing is set up in a jig where all measurements are checked in preparation for brake flange installation.
15 Frank Ferrell (background)...
15 Frank Ferrell (background) and Juan Alaniz set up our housing for brake flange installation, which is checked with this digital level. No guesswork here, just pinpoint accuracy.
16a There are a number of...
16a There are a number of hubs and drive plates available from Speedway Engineering depending upon what you want your full-floater to do, and what kind of wheels you are going to run.
16b This is the lightweight...
16b This is the lightweight aluminum Mod-Lite hub with Mod-Lite drive plate and full-floating snout. What you have here are large heavy-duty hub components that can take greater amounts of punishment than a conventional semi-floating setup.
17 Here's the steel Mod-Lite...
17 Here's the steel Mod-Lite hub with steel drive plate. The Mod-Lite provides extremes of durability via lightweight steel alloy technology. We opted for the Mod-Lite due to its 2.780-inch register size, which we needed to utilize the upcoming wheel package we're planning to use that features a 2.858-inch wheel register opening.
18 Primarily engineered for...
18 Primarily engineered for stock car racing, you will likely never have call for the A356 aluminum Wide 5 hub. However, it weighs less and provides even greater strength.
19 Although there are a variety...
19 Although there are a variety of axle types available, you have a basic choice of crowned (right) and straight (left) depending upon what you want the axle to do. And, you must have a corresponding drive plate to go with either the crowned or straight spline axleshaft. Crowned axleshafts can only be used with steel drive plates. The crowned hub axle articulates around its centerline (camber) whereas the straight does not.
20 The full floater offers...
20 The full floater offers better load distribution without placing extreme stresses on the drive axles. The bearings ride on this large snout (hub). And because the bearings are larger than we see with semi-floaters, load is more widely distributed. Axles get torsional loads without having to carry vehicle load.
21 Hanging upside down in the paint booth, our new Speedway Engineering 9-inch housing is ready for paint (or powdercoat if you prefer). Be sure to check back as we stuff the 9-inch with a stout third member and add Wilwood's trick full-floater rear brake system.