Fifth-Generation Toyota 4Runner Sway Bar Bushings: Symptoms, Fitment and Replacement

Do You Need New Sway Bar Bushings?

Replace the stabilizer bar bushings on a 5th gen 4Runner when an inspection shows they are cracked, torn, compressed, oil-soaked or no longer holding the bar firmly in its brackets. Age or mileage alone is not a reliable trigger, and Toyota does not publish a universal replacement interval for these bushings in the general maintenance schedule. They are normally checked as part of a suspension inspection and replaced on condition.

The important qualification is that a clunk from the front end is not proof the bushings are worn. Sway bar end links, upper and lower control arm bushings, ball joints, shock mounts and loose skid plates can all produce similar noises. Buying bushings is reasonable only after you have narrowed the noise down to the bar mounts. If the bushings are the cause, they are an inexpensive part, and replacing them in pairs restores even support on both sides.

How Sway Bar Bushings Work

The stabilizer bar is a steel bar that connects the left and right sides of the suspension. When the body leans in a turn, one wheel moves up relative to the other and the bar twists, resisting that lean. The center section of the bar is held to the frame by two brackets, and each bracket clamps a bushing around the bar. End links connect the ends of the bar to the suspension.

The bushings let the bar rotate slightly in its mounts while keeping it located and isolating metal-to-metal contact from the frame. Over time, rubber can harden, crack or take a set, leaving a gap between the bar and the bushing. That gap allows the bar to shift when the suspension loads and unloads, which is where the knock over speed bumps or driveway transitions comes from. Dry or contaminated bushings can also squeak as the bar rotates, especially in cold weather or after a wash.

What Changes the Answer for Your 4Runner

The biggest factor is whether your truck has KDSS, the Kinetic Dynamic Suspension System offered on certain fifth-generation trims. KDSS uses hydraulically linked front and rear stabilizer bars instead of a conventional fixed setup, so the bars, mounts and service procedure differ from a non-KDSS truck. Bushings and brackets are not automatically interchangeable between the two, and KDSS work involves specific valve and leveling steps in the factory service information. Confirm which system you have by trim and VIN before ordering anything.

Bushing inner diameter must match the bar it clamps. If a previous owner installed an aftermarket sway bar, the factory part number may no longer apply, so check the service history or measure the bar. Model year and trim can also change part numbers across the long production run of this generation, and some trucks may have a rear bar while others are set up differently depending on equipment. Lift kits do not usually change the bushings themselves, but they can change end link geometry and load, which affects how quickly related parts wear.

Operating conditions matter too. Off-road articulation, road salt, mud, and oil or fluid leaks onto the bushings all accelerate deterioration compared with mostly paved highway driving. A truck used on trails deserves more frequent inspection of the whole sway bar assembly.

How to Check and Choose Replacement Bushings

With the truck safely parked on level ground, look at the bushings where the bar meets the frame. Signs of wear include visible cracks, rubber squeezed out of the bracket, a polished or rust-free band on the bar showing it has been moving, and a visible gap between bar and bushing. Have a helper rock the vehicle side to side or push down on a fender while you watch the bar; it should not shift or clunk inside the brackets. Then check the end links for torn boots or play at the ball studs, because they are a frequent source of the same complaint.

When shopping, the main choice is OEM-style rubber versus polyurethane. Factory rubber bushings prioritize quiet operation and ride comfort and match the original design. Polyurethane bushings are firmer and resist deflection, which some owners prefer for a tighter feel, but they can transmit more vibration and often need periodic lubrication to stay quiet. Use only the lubricant the bushing manufacturer specifies, and do not apply petroleum-based grease to rubber bushings, since it can degrade them.

Match parts by VIN, trim and KDSS status, buy both sides together, and consider replacing brackets if they are bent or heavily corroded. If the end links also show wear, doing them at the same time saves a second teardown. Tighten all fasteners to the values in Toyota's manufacturer specifications for your exact model year, with the suspension at the loading position the procedure calls for, so the bushings are not preloaded in a twisted position.

Limitations and When to Get Professional Help

Noise diagnosis by ear and by eye has limits. A clunk that persists after new bushings, or one that changes with braking or steering rather than body roll, points to another component. A shop with a chassis ear or lift can isolate the source far more reliably than a driveway inspection, and that can save you from buying parts the truck does not need.

On KDSS-equipped trucks, have the work done by someone who follows the factory procedure, or obtain the service information for your model year before starting. Incorrect handling of the system can leave the vehicle leaning or with altered suspension behavior. For any 4Runner, if you are unsure about fastener torque, lifting points or part fitment, the safest next step is a professional suspension inspection, followed by ordering bushings that are confirmed for your exact configuration.