Independent front suspension

Also called IFS, independent suspension, A-arm front end

Independent front suspension lets each front wheel move up and down on its own, which rides, steers and handles better on the road than a solid axle, at the cost of articulation, clearance under the front differential and some ultimate strength.

What is independent front suspension?

Two ways to hang a front axle. A solid axle is a single beam across the vehicle with a wheel at each end: lift one wheel and the other tilts with it. Independent front suspension replaces the beam with a pair of control arms on each side and a differential bolted to the frame, driving the wheels through CV shafts. Each wheel moves alone.

Almost every modern truck and SUV sold in the United States is IFS, including the Tacoma, the Ranger, the Colorado, the Ram 1500 and the F-150. Solid front axles survive mainly on the Jeep Wrangler and Gladiator and on heavy-duty pickups such as the Ram 2500 and 3500 and the Ford Super Duty.

What each is good at

IFS gives you a vehicle that steers accurately, does not wander at highway speed, does not shake its own steering wheel over a bump, and rides far better unladen. It has less unsprung weight, so it copes better with high-speed rough ground, which is why desert racing trucks are IFS.

A solid axle keeps both wheels the same distance from the ground under it, which means it puts more weight on a wheel that has dropped into a hole. It has fewer joints to break, more clearance under the pumpkin when you lift it, and much greater articulation, which is what you want on slow technical rock.

What IFS costs you off-road

Articulation, mostly. The control arms limit how far one wheel can drop before it stops being loaded, and a lifted wheel is a wheel making no traction. It also means the front differential and the lower control arms hang below the frame, so a suspension lift raises the body away from them without raising them at all.

Lifting IFS is also more involved than lifting a solid axle. Push it too far and the CV shafts run at angles they were not designed for, which is why serious lifts come with differential drop brackets or replacement upper control arms rather than just longer springs.