Enhancing Your F150’s Drivetrain Durability: Aftermarket Driveshafts

Depending on the year and cab and bed configuration, F150 pickups come with either a one-piece driveshaft or a two-piece driveshaft. It depends entirely on the wheelbase of the truck. A shorter wheelbase truck can get away with a one-piece driveshaft whereas longer trucks must use a two-piece shaft. To tell which your truck has, simply look underneath. Two-piece shafts will have an additional central support mount that is quite easy to identify.

OEM driveshaft material is mainly steel. However, some factory one-piece driveshafts are indeed made from aluminum. Determining which shaft your truck has can be done using a magnet. If a magnet won’t stick to the driveshaft, then you have an aluminum version.

It is difficult to source an exact number at which the factory driveshaft is rated to. Rather, digging through many online owner reports, it seems that the bulk of driveshaft failures are related to two scenarios: 1) driveshaft tears due to stress when off-roading (where the wheel is slipping then suddenly bites – most commonly the front driveshaft of 4WD breaks under this circumstance), and 2) seized u-joints. 

Moreover, there are exponentially more complaints concerning odd driveline harshness, vibrations, or thuds through all phases of driving. These driveline symptoms have been an issue that has plagued F150 pickup trucks for multiple generations, with the real cause remaining a mystery for the most part as some trucks suffer from it time and time again whereas others go their entire life without issue. Furthermore, any problem with the OEM driveshaft necessitates replacement of the entire system (shaft, central carrier, and u-joints) as it is a non-serviceable unit.

If your truck is currently suffering from a similar driveline symptom or you want to prevent yourself from blowing a shaft out on the trail and possible becoming stranded, aftermarket units are readily available to take care of problem one and beef up problem two.

Aluminum has two significant advantages over a steel-fabricated driveshaft. First is weight. Being lighter than steel, an aluminum driveshaft absorbs less horsepower than a heavier steel shaft and therefore transmits slightly more power to the wheels while also allowing the engine to rev up in less time.

Secondly, due to its weight advantage, aluminum driveshafts can be made longer and spin faster before reaching their critical speed. At a certain RPM, which is determined by length, diameter, material density, and elasticity, the driveshaft will begin to resonate, vibrate, and harmonically unravel itself like a roll of toilet paper.

An aluminum driveshaft has a larger diameter and thicker wall than a comparable steel tube, both of which positively improve driveshaft balance and allow the shaft to be longer without bending. This is ideal for an F150 pickup, where due to its extended wheelbase, a two-piece driveshaft has to be used in order to prevent the OEM system from reaching its critical speed. All said and done, aftermarket aluminum tubes are generally built to withstand 900-1000 horsepower.

Carbon fiber poses the same advantages of an aluminum driveshaft and then some. It is even lighter than aluminum which helps reduce the rotating mass of the drivetrain. Strength wise, carbon fiber offers the best strength-to-weight ratio of any driveshaft material. Furthermore, due to it being composed of many individually weaved layers, carbon fiber tubes have excellent vibration and dampening abilities. Overall, carbon fiber driveshafts are the best that money can buy and will handle an intense amount of horsepower.

Having said all that, however, outfitting a carbon fiber driveshaft on your F150 is NOT a good idea. While yes, they are super strong and can withstand 1000 plus horsepower, one area that carbon driveshafts do not fare well in is robustness. They are susceptible to surface damage, where a scratch or nick in the carbon can (and likely will) eventually lead to failure. Given the off-road driving abilities and context of an F150 pickup, where under vehicle trail obstacles are frequent and prominent (rocks, branches, brush, etc.), a carbon fiber tube is easy and likely to get bashed up. Although on the plus side, when a carbon fiber shaft does break, it usually just shreds itself to bits and is less likely to take out other components (unlike a metal-based driveshaft, when these go, usually they try and take everyone down with them).

A properly balanced driveshaft in and of itself is extremely important. Unbalanced, it will create unnecessary vibration and harshness. Not only is this uncomfortable for the occupants, but it will also place unnecessary wear on the other driveline components that may end up causing them to fail prematurely. Like how wheel balancing is done, most driveshafts are balanced using external weights and are balanced for a particular RPM (typically the common driving range of 2000-4000 RPM).

Now, most driveshafts are balanced this way, but not all. Some high end aluminum shafts are balanced by removing material. Certainly more in-depth and time consuming, this method eliminates the chance of losing a balancing weight (it falls off) and thereby causing the shaft to become unbalanced.