2020 Subaru Outback Suspension Deep Dive | More than meets the eye

The 2020 Subaru Outback is a completely redesigned car. It has a lot to offer in terms of new convenience features, and the driving experience is much improved. A good deal of that comes from chassis improvements, and indeed a lot of work went into making the body shell and suspension subframes more rigid so the suspension attachment points could be more robust and stable.

Don’t let all of that rigidity talk make you think the ride itself is stiff. It isn’t. Any suspension tuning engineer will tell you that a stable platform is necessary even if a smooth ride is the goal. Rigid attachment points make it easier to control ride motions and road imperfections within those components designed for that very job – the springs, dampers and suspension bushings.

So let’s take a look at what Subaru has done under the new Outback. What we’re about to see doesn’t just apply to the Outback wagon, but to the closely-related and also-redesigned 2020 Legacy sedan as well.

It’s no surprise that a vehicle like the Subaru Outback uses strut front suspension, but from here, a couple of details do look curious.

Like any strut suspension, the steering axis (yellow line) is defined by the pivot bushing at the top of the strut and the center of the lower ball joint. The entire affair will pivot about this line when the wheels are turned.

The lower control arm (red) of the newly redesigned 2020 Outback is now a lightweight aluminum piece instead of the steel hunk that was used last year. As before, there’s a “direct-acting” stabilizer bar link (green) that attaches to the strut housing, an arrangement that maximizes the efficiency of the stabilizer bar because the motion ratio is 1-to-1 motion with respect to wheel movement. As for the stabilizer bar itself, it’s now hollow to save a bit of weight.

This spacer (yellow) raises the body relative to the suspension. The Outback has one, but the lower-riding Legacy sedan does not. The spacer pushes the arm down (or the body up - take your pick), so that means the Outback’s reinforcing bracket (green) will also differ from that of the Legacy.

While we’re here, look at the round rubber bushing just below the spacer. That void space and square nub you see pointing directly at you will make sense in a short while.

Subaru couldn’t simply put a spacer on the Outback’s rear lower control arm pivot and call it good. They had to do something of similar magnitude at the front. But the front subframe (green) is one big piece from top to bottom. What they did was slide a long flat spacer block (yellow) between it and the Outback’s body. It’s hard to see behind the spot weld seam that hangs down, but it is up in there – and it’s as thick as the spacer we saw in the last image. The Legacy doesn’t have this, so its subframe would look thinner because more of it would slip up and in behind the down-hanging body weld seam.

The front and rear lower control arm pivots are braced with a broad plate (yellow) at the bottom to give these critical front suspension pivot points extra strength. Its forward edge has a big u-shaped gap, and that’s there to accommodate the passage of the flat-four engine’s exhaust system.

The lower control arm has a distinct L-shape. The upward component – the shock – goes up into the spring and damper no matter what. Lateral cornering loads (yellow) will primarily act on the forward bushing of the L-shaped arm.

But the load path changes when you hit a pothole or other sharp-edged bump because there is always a rearward component – the harshness. Here, the front bushing is more of a pivot point. The rearward impact at the ball joint (green) is turned through approximately 90 degrees to become an inward pulse at the rear bushing. This is where the bushing’s void and square nub we saw earlier come into play. Those features are calibrated to allow just enough give to take the edge off the incoming pulse while still maintaining control.

It’s not surprising to see that the lower control arm’s inner pivot (yellow) doesn’t have any provision for camber adjustment. That’s never something you see on strut front suspensions with an L-shaped lower arm. That said, the Subaru Outback does provide a way to adjust camber. It’s hidden within the upper strut mounting bolt (green).

Two-bolt strut mounts are fairly common, but they don’t usually give you any easy way to adjust camber. Struts aren’t meant to be adjustable, in most cases. Some parts catalogues will have “crash bolts” with smaller shafts that can be substituted if the need arises to provide slop that you can manipulate to make crude adjustments, but that’s a bad way to go for a number of reasons. Mainly, they don’t hold their adjustment well at all.

Subaru’s approach is a more refined version of the crash bolt concept that’s far more stable. The lower bolt is just a bolt in a round hole, but the upper one (yellow) has an internal eccentric that rides in a vertical slot. You have to loosen both, of course, but once that’s done you can rotate the upper bolt head (on the hidden far side) to move the eccentric to make your camber adjustment. There’s never any in-and-out slop like there is with a reduced-diameter crash bolt, so the adjustment holds firm once you torque things tight.

Even with the wheels on, you can always tell (or nearly always) if a vehicle’s steering linkage works ahead of the front axle or behind. In almost every case it’ll be opposite the side that the brake calipers are on. It’s easy to see how they can’t share the same space from this vantage point.

Most front-drive-based crossovers will have front-mounted brakes and rear-mounted steering because a transverse engine and its transmission occupies the space where front-mounted steering would go. But the Subaru’s longitudinally-mounted flat-four engine allows for the use of front-mounted steering (green), and so we see rear-mounted brakes. From this vantage point we can also make out the dual pistons (yellow) that power these sliding caliper brakes.

Even from this distance we can see that the rear suspension is most definitely not strut-based. There’s a nice aluminum upper wishbone, a coil-over spring/shock assembly, and a few other interesting bits.