Suspension Wars: Solid
Beam axles have always ruled king when it came to off-road. Even decades after they’ve been displaced by the better handling Independent Front Suspension (IFS) alternative, they are still viewed as the go-to option when heavy-duty is needed.
Solid axles are extremely simple in their design, featuring a center-section that contains the differential, axle tubes, inner and outer knuckles, axle shafts, bearings, ball joints and the braking system. IFS systems have all those same components (with the exception of the axle tubes being replaced by torque tubes) plus they house the entire suspension system as a component and the supporting frame or unibody of the vehicle is exclusive to that specific IFS setup.
Needless to say, solid axles are way simpler, which is why they’ve retained so much of their support over the years, and why they are still looked to as the HD standard. Beyond their simplicity and their durability – the suspension that is connected to them share those same traits. There are two options with a solid axle, leaf springs or link. Leaf springs in the front suspension are the same as they are in the rear, so that is nothing new. Link systems however, have dozens of different layouts to accomplish different needs. We won’t go into the specifics of all those link options in this article, but if you want to blow your mind, look up “Double-triangulated Four-link suspension.”
These days, five-link suspension systems are the go-to options for front solid axle suspension options and is the method used by all of the major automakers still offering solid axles. A five-link setup is exactly what it sounds like. There are five points that hold the axle place: four control arms and one track-bar for side-to-side movement.
While this setup is much more complicated than a leaf-spring setup, it allows for full adjustability and control of the axle and extremely high levels of articulation when off-road compared to a leaf setup, and is incredibly durable and high-clearance. This setup is so revered in its capability that RAM Trucks have even gone as far to implement this suspension design into the rear axles of all their light and heavy duty trucks.
While IFS may reign as the go-to setup by manufacturers these days, a solid axle can’t be beat off-road. That is unless you are doing 100 mph, but we will leave that for the trophy trucks and Raptors.