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Ford Mustang Rear Axle Upgrade - Buns Of Steel - Tech
All the parts and pieces to strengthen your 8.8-inch rear.
Late-model Ford owners are a fortunate bunch. It's easy to make your Blue Oval machine stomp the competition with copious horsepower, and these days the transmissions aren't too bad, either. The last link to getting the power to the ground is what lies under the rear flanks of your Mustang or other fast Ford-in most cases, it's the tried-and-true 8.8-inch rear. Whether you start off by adding stronger axles or go the whole nine yards and order a complete, professionally built rear, making the 8.8 live behind your powerful Ford engine is key to going fast.
For some, making hellacious horsepower is their only concern. While dyno numbers are a surefire way to back up the smack talk about how fast your ride is, a timeslip will back up any dyno flog. But if your rear breaks or flexes, it can't supply all that power to the tires.
Getting down the dragstrip can be a demanding task, especially when it comes to the final link of the chain. While a factory rear can handle the output from a stock or mildly built powerplant, when the horsepower scales tip to the "heavy" side, the 8.8 can only stand so much before it goes on a permanent vacation.
Hooking too hard can also cause damage that may be unfixable if your rear is stock. We've seen axle tubes twist away from the centersection, and we encountered a housing that literally split in two. That's why we first recommend welding the axle tubes to the centersection to prevent them from spinning out of the vehicle. Then you can add a rear girdle, which adds strength over the stock cover and limits the movement of the differential when the power is on.
On launch, the differential tries to drive right out the back of the housing, but a properly installed girdle will help keep it in place by applying a small preload to the housing main caps. Also, consider aftermarket axles, which are inherently stronger than stock units. Next should come a strengthened differential that can handle the extra power.
To keep the rearend together no matter how much power your Stang is pumping out, check out the following parts and pieces that will help beef up your buns into buns of steel.