We’re a year in with the new S-550 Ford Mustang and its independent rear suspension. The drag racers still gripe they have no solid rear axle, but at least Ford Performance has given them and track hounds a bone.
The stock suspension and rear axle assemblies are more than enough for the street and the stock engines found in the new Mustang. But, if you’re planning to drag race a lot, play on the road course, or add more power to your 5.0, you may need to tighten things up.
In that way the fix has been in from the start, with Ford Performance parts offering exactly what you need to beef up the durability of the rear drive axle assemblies as well as tighten the suspension so the wheels stay planted.
The prescription for loving long time comes in two bottles, the Ford Performance Mustang Rear Sub-frame with Bushings (M-5035-M) and the Mustang Half-Shaft Upgrade Kit ( M-4130-M). These are both shown in the video below.
You can use one without the other, though in most cases if you want one, you will want the other.
The Mustang Half-Shaft Upgrade Kit is a must if you add major power to your 5.0 such as with a supercharger or turbocharger, and perhaps even if you spray. These CNC machined shafts are made for “severe duty”.
Their design keeps their weight as light as it can be for their strength and Ford Performance says they help to reduce wheel-hop. At the very least they should reduce breaking in half and sending you into a wall.
They have one-piece billet ends, replaceable CV joints and come with a 2 year warranty. They’re actually sourced from G-Force Engineering, which means you might find them elsewhere for less. Ford Performance retail price is $1,895 for the set.
The second half of the fix is keeping your rear suspension from doing the shake, rattle and roll when you send all that extra power back there. Normally, it’s simple. You just put in stiffer bushings for the cradle and differential.
Unfortunately, with all the pressed in variety of bushings involved here that is major brain damage so Ford Performance just put them all together in a fresh new rear sub-frame assembly to make it all easier.
Stiffer bushings keep the cradle and differential from moving around and getting into the rhythmic oscillations which can not only feel sloppy but cause wheel-hop. This will make your Mustang feel better whether on the road course or the drag strip.
It is an expensive way to get a fresh set of bushings back there however at a retail price of $1,119. But if you think of the labor time saved in beating to death your old bushings and finding a way to press new ones into your existing sub-frame – well, just inhale. Spend the money.