Most fourth-gen 4Runners still on the road are 15 to 20 years old, and a lot of them are still riding on factory struts or cheap replacements. You feel it as a nose that dives under braking, a front end that keeps bobbing after a dip, or excessive side to side sway when on forest service roads or trails. These Bilstein 6112s replace all of that and lift the front while they're at it, but calling them a leveling kit sells them short. The 2.6-inch monotube body and 60mm digressive piston carry far more oil and damping control than the strut they replace. Your 4Runner gets a front end that feels tighter than it did new, with the height set where you want it. You're now free to roam around the wilderness.

We take it one step further. The 6112 normally shows up as a box of loose parts: dampers, springs, spring seats, and circlips, with a note that says "spring compressor required." Bilstein's kit also reuses your factory upper mounts. We build them for you, at the height you choose, with new OE-spec upper mounts, so what shows up at your door is two finished coilovers ready to bolt in to your 4Runner, or save you a couple hours of labor at a shop.

How We Build Them

Every pair is built to order after you pick your engine, drivetrain, and lift setting above. Here's what happens on our bench:

• Set the circlips. The 6112 body has a row of numbered grooves, and where the circlip sits decides your ride height. On the 4Runner, Bilstein uses the same groove on both sides. We set each coilover to the setting you ordered.
• Seat the billet spring perch. The anodized aluminum spring seat sits on the circlip and carries the spring.
• Compress and install the Bilstein spring. We use a mounted, shop-grade strut compressor. This is the step that makes DIYers nervous, for good reason: a coil spring under load stores a lot of energy.
• Install a new OE-spec upper mount. The rubber in your factory mounts has been soaking up every pothole for 15-plus years. Reusing tired mounts on fresh coilovers is like putting new tires on bent wheels. New mounts come on every build.
• Torque, check, label. The top nut gets torqued to spec, each coilover is checked and marked driver or passenger, and the pair is boxed together.

Why Buy Them Assembled?

• No spring compressor. Rental "clamshell" compressors are the most dangerous tool most people will ever use in a driveway. You skip that part entirely.
• No mismatched sides. A common 6112 mistake is setting the two sides one groove apart by accident, which leaves the truck leaning. Ours are set and checked as a pair.
• New mounts included. The loose Bilstein kit reuses your factory upper mounts. Ours come with new ones.
• Faster install. Assembly is the slowest part of a coilover job. With that done, the job is removing two struts and bolting in two.

Bilstein doesn't approve every setting on every 4Runner, so we only build the settings in the dropdown. No 2003-2009 4Runner gets a stock-height setting on this kit: the lowest is 1.3" on the V8 4WD and 2.5" on the V6 RWD.

How to choose: Measure from the center of each wheel to the fender lip, front and rear. The difference is your rake. If you want the truck level on the stock rear coils, pick the setting closest to that number. Adding rear coil springs or a rear spacer? Add that rear lift to the rake. Running a steel front bumper or winch? Go one setting higher to make up for the weight. Stuck between two? Call us with your measurements and we'll pick it with you: (213) 433-3616.

Matching the Rear: Bilstein 5100 or 5160?

The 4Runner rear is a coil-sprung solid axle on a 4-link, not leaf springs, so rear height comes from the coils (or a spacer), and the shock just has to cover that height. Bilstein builds both a 5100 and a 5160 for it. The choice comes down to how high the rear sits and how hard you work it.

The Bilstein 5100 (33-313146) is the default. It uses a 46mm digressive piston in a zinc-plated monotube body and covers stock height up to 2" of rear lift (23.5" extended, 14.91" compressed, 8.59" of travel). It replaced 33-187174. With Bilstein valving at both ends, the front doesn't feel sharp while the rear floats around on tired stock shocks.

The Bilstein 5160 (25-311211 left / 25-313130 right) is for loaded or lifted rears. The remote reservoir adds oil capacity, so it runs cooler and fades less on long washboard roads and with weight in the back. It covers up to 2.5" of rear lift.

Run the 5100 if:

• You're keeping the stock rear coils, or adding up to 2"
• The truck is mostly pavement and dirt roads, with the occasional trail weekend
• You want Bilstein control front and rear without spending reservoir money

Run the 5160 if:

• You're running taller rear coils or a spacer that lifts the rear up to 2.5"
• The cargo area and roof carry real weight: a drawer system, a rooftop tent, a hitch carrier, regular towing
• You spend long stretches on washboard or desert roads, where a shock without a reservoir heats up

When you need something else: More than 2.5" of rear lift needs a longer shock. Call us and we'll size one to your setup: (213) 433-3616.

Shop the Bilstein 5100 Rear Pair for the 2003-2009 4Runner

Shop the Bilstein 5160 Rear Pair for the 2003-2009 4Runner

On the Road

Bilstein tunes for control first. Compared to worn factory struts, expect a tighter front end: less nose dive when you brake, less body roll on on-ramps, and a front end that settles after a highway dip instead of bobbing. On a 4Runner this tall and this heavy, that's the difference you feel most. If you want a pillowy ride, this isn't it, and we'd rather tell you now than after the install.

Off the Road

The 2.6-inch body holds more oil than the factory strut and sheds heat better, so damping stays consistent on long washboard roads instead of fading. The digressive piston stays firm on small, quick inputs and opens up on bigger hits. One thing it won't fix is the rear. On rough roads, a 4Runner's rear end bounce and wallow come from the stock rear shocks and coils, so plan on a rear shock to match (see above).

The Honest Trade-Offs

• There's no stock-height setting. Every setting on this kit lifts a 2003-2009 4Runner: 1.3-3.6" on the V8 4WD, 2.5-3.7" on the V6 RWD. If you want to stay at factory height, call us and we'll point you to a stock-height setup.
• Your height is set when we build it. Changing it later means taking the coilover apart with a strut compressor. Measure before you order.
• Firmer than stock. See "On the Road" above.
• Built to order. Every pair is assembled for your truck, so it takes longer to ship than a box pulled off a shelf.
• The top settings need supporting parts. This kit goes higher than most 6112 applications. From about 2.5" up, the factory upper control arms and ball joints run at steep angles, the truck gets harder to align, and the CV axles on 4WD trucks work harder. Aftermarket upper control arms help the alignment get back in spec and keep the ball joints happy. The V6 RWD starts at 2.5", so plan on arms for every V6 RWD build.
• The rear has to keep up. At 2.5" and up in front, most 4Runners need rear coils or a spacer to avoid a nose-high stance.
• Don't stack a spacer on top. A strut spacer on top of a 6112 pushes the front past what the factory arms and axles are built for.

Install Notes

• Fits 2003-2009 Toyota 4Runner: V8 4WD and V6 RWD. Choose your engine and drivetrain above; the height settings are different for each.
• V6 4WD owners: call us before ordering. Bilstein's chart for this kit lists the V8 4WD and the V6 RWD only.
• X-REAS or rear air suspension: call us before ordering. Some Sport Edition and Limited trucks came with X-REAS cross-linked shocks or rear height-control air suspension, and those trucks need a different plan.
• For a 2010 or newer 4Runner, see our 5th-gen 4Runner 6112 listings.
• Removing a strut spacer? Leave it off.
• Get an alignment right after install. Any lift changes camber and toe.
• Recheck the front height after the springs settle in over the first few hundred miles.
• Most people with a floor jack, jack stands, and a basic socket set can swap the pair in an afternoon. The heavy lifting is done.

Who Should Buy These

Fourth-gen 4Runner owners who want real front lift and a real damper upgrade instead of a spacer, with no spring compressor anywhere near the driveway. It's a great fit for daily drivers that see dirt roads, weekend trail trucks, and overland builds carrying armor and gear up front. If you want a milder lift and the budget is tight, the Bilstein 5100 lift system gets you the stance and Bilstein control front and rear for less.