A drive shaft transfers power from the transmission to the differential of the car, and the differential then sends power to the rear wheels of your Mustang. A drive shaft is a simple round shaft, uncomplicated and easily ignored, but without a driveshaft, there’s no way for your car to efficiently transfer energy into motion.
Upgrading your driveshaft isn’t a flashy performance upgrade, but it is one that you may need to consider based on your ideal build. Though most cars come with a steel drive shaft, at some point you may decide to replace the steel stock driveshaft with one made out of aluminum or carbon fiber. All three driveshaft materials have pros and cons that make them ideal for different types of drivers.
By far the most inexpensive option, steel driveshafts have the benefits of being durable and dampening noise and vibrations through your vehicle.
The downsides are that steel is obviously heavy and in addition to contributing unnecessary weight to your vehicle, a steel drive shaft also makes your engine work harder because it has to rotate the heavy drive shaft in order to move the vehicle.
A steel driveshaft
Typically, stock drivetrains will be made out of steel because they require the least maintenance and provide the most comfortable ride for the everyday driver. For many enthusiasts though, the steel drivetrain is one of many things that can be cut to easily save on weight, which makes a difference not only for drag racing but also for many autosports like drifting or autocross.
There are different types of steel driveshafts and they aren’t all the same. Chromoly steel tubes are heavy, but they’re also very strong and can survive high speeds. On the other hand, seam tube is usually what the stock driveshaft is made out of and though it’s inexpensive, it’s also pretty weak compared to other steel forms.
An aluminum driveshaft
Going from a steel to an aluminum driveshaft is one way to decrease the amount of excess weight your car is carrying around as well as to reduce the workload that is being passed along to your engine. Aluminum driveshafts are significantly lighter, and, depending on what year Mustang you have, you could be dropping anywhere from ten to twenty pounds simply by making the swap from steel to aluminum.
Dropping a drive shaft is particularly beneficial since it isn’t static weight you’d be dropping but rather rotating weight. This means that it’s the equivalent to dropping significantly more weight.
The downside to aluminum is that it’s much more fragile than steel, and when aluminum breaks, it shears, creating dangerous sharp edges that could harm your car or even yourself. Aluminum also is a much noisier drivetrain that doesn’t reduce vibrations in the same way that steel does. This makes it less comfortable for casual drivers. Aluminum is overall not a very strong metal, and it does poorly at high speeds.
In addition to being light though, Aluminum doesn’t respond to weather as negatively as steel does, and so many people in snowier areas are excited to upgrade to aluminum just because aluminum is immune to rust. It should be noted though that aluminum is easily corroded though, so it’s important to inspect your aluminum driveshaft regularly.
A carbon fiber driveshaft
Carbon Fiber driveshafts offer the greatest weight savings. Though aluminum driveshafts are impressively light, carbon fiber shaves a few additional pounds off. This isn’t the greatest advantage of carbon fiber though. Unlike steel or aluminum, carbon fiber doesn’t sheer when it breaks. Instead, if it breaks, carbon fiber comes apart in harmless splinters that are unlikely to damage your vehicle.
Carbon fiber is stronger than steel even, and its vibrations are significantly less than aluminum.
In short, it’s the perfect material, except for a few small things. Carbon fiber is impossible to repair, it can only be replaced. Unlike steel or aluminum which can be soldered, with carbon fiber if a universal joint is damaged than the structural integrity of the whole is irrevocably damaged.
This would be tough enough if carbon fiber drive shafts were similarly priced to their steel and aluminum counterparts, but carbon fiber is a specialized material that is difficult to make, so they’re also substantially more expensive.