Torque Rod Bushes with Fitting Position Rear Axle

A torque rod is a locating link that stops part of the suspension or driveline from twisting or shifting under load. Its bushes sit at each end, where the rod meets the chassis and the axle or suspension arm, and they carry the forces from every take-off and every brake application. The term covers a few different parts depending on the vehicle, but the job is the same: keep things where they belong when torque tries to move them. On a 4WD that tows, works in low range or carries a heavy load, that is a lot of force, and worn torque rod bushes tend to announce themselves with a clunk. Use the vehicle search to find torque rod bushes to suit your 4WD.

What a Torque Rod Actually Does

When an engine sends torque through the driveline, the axle tries to rotate the opposite way. Under braking, the reverse happens. This is called axle wind-up, and if nothing controls it, the axle twists on its mounts, the pinion angle changes and the wheels can hop.

A torque rod resists that movement. On some vehicles it is a dedicated link that controls axle wind-up. On others, particularly some older independent front 4WDs and utes, a front torque rod or tension rod locates the lower control arm fore and aft, holding the front wheel in place under braking and acceleration.

The bushes at each end let the rod pivot as the suspension moves, while resisting the twisting and pulling forces it is there to control.

Torque Rod or Track Rod?

The names sound similar but the parts are different. A torque rod locates the axle or suspension. A track rod, also called a tie rod, is a steering part that connects the steering box or rack to the wheels. Torque rod bushes have nothing to do with the steering linkage.

Torque Rods, Torque Arms and Strut Rods

Manufacturers use different names for similar parts. A torque arm usually describes a longer link that controls axle wind-up. A strut rod or tension rod usually describes a link that locates a lower control arm. Some vehicles call one of these a torque rod. The vehicle search shows which parts suit your 4WD, whatever they are called.

Does Your 4WD Have Torque Rods?

Many do not. Most current utes use leaf springs at the rear, where the spring itself controls axle wind-up, and two-piece control arms at the front. Coil sprung solid axle 4WDs typically use radius arms or trailing arms with upper links.

Torque rods are more common on some older independent front 4WDs and utes, some heavy-duty trucks and some specialised suspension setups. A look under the vehicle will usually show whether there is a separate rod running from the axle or lower arm to the chassis.

Signs Your Torque Rod Bushes Are Worn

A clunk when taking off or braking is the most common sign. As torque loads the axle or arm, it moves in the worn bushes until it hits the end of the slack, and the knock comes through the chassis.

Axle tramp or wheel hop under hard acceleration, particularly when towing or climbing in low range, can point to worn bushes letting the axle wind up.

On front torque rods that locate the lower control arm, worn bushes can cause wander, a pull under braking and uneven front tyre wear, because the wheel position changes as the brakes load the front end.

On inspection, look for cracked, split or squashed bushes, rubber pushed out from under the washers, or a rod that moves in its mount when levered.

Worn leaf spring bushes, control arm bushes, diff mounts and engine or gearbox mounts can cause similar symptoms, so a full inspection is worth doing first.

Loaded, Towing and Low-Range Considerations

Towing

Towing is hard on torque rod bushes. Every take-off pulls the trailer through the driveline and suspension, and every stop pushes it back. That is exactly the force the torque rod controls. A 4WD that tows regularly can wear these bushes noticeably faster.

Low Range

Low-range work multiplies the torque reaching the axles. Climbing a steep section or crawling over rocks puts high wind-up forces through the torque rods, and worn bushes let the axle move further than it should.

Heavy Loads

A loaded 4WD needs more torque to move and more braking force to stop. Both increase the load through the torque rod bushes.

Lifted Vehicles

A lift changes the angle of every suspension link, including torque rods. If the bolts are tightened with the suspension hanging, the bushes sit permanently twisted at ride height and wear faster. After a lift, the bolts should be tightened at the new ride height.

Rubber or Polyurethane Torque Rod Bushes?

Factory torque rod bushes are usually rubber. Rubber isolates vibration and shock, but it deflects under load, and as it ages it softens and cracks, letting the rod move further.

Polyurethane torque rod bushes are generally firmer. They hold the rod more precisely, which can reduce clunks on take-off and braking and help control axle wind-up. The trade-off can be a little more vibration reaching the chassis.

What Comes in a Torque Rod Bush Kit

Kits vary by vehicle. Some cover one end of the rod, some both ends, and some both sides of the vehicle. Sleeves, washers and lubricant may or may not be included. Check the product details for which positions the kit covers and what is supplied.

Replace the Bushes or the Rod?

New bushes are usually the fix when the rod is straight, free of cracks and its mounting points are sound.

The rod needs replacing when it is bent, cracked or heavily corroded, or when its bush eyes have worn oval. A bent torque rod changes the axle or arm position, and new bushes will not correct it. Damaged chassis or axle brackets need attention as well.

Fitting Torque Rod Bushes

Replacing torque rod bushes is a job for a qualified technician. The vehicle is supported on rated stands, and the axle or arm is supported so the rod can be removed safely. The old bushes are pressed or pulled out, the rod and mounts are cleaned and checked, and the new bushes are fitted with the correct washers.

The rod is refitted and the bolts are tightened with the vehicle at ride height, so the bushes start in their neutral position. All fasteners are torqued to specification. Where the rod locates a front control arm, a wheel alignment is required afterwards. A road test, including take-off, braking and some towing or low-range work where relevant, confirms the clunk has gone.

How Formula 4x4 Can Help

Formula 4x4 works across the whole 4WD suspension and driveline, which is useful on a part that goes by several names. If you are not sure whether your vehicle has a torque rod, a torque arm or a strut rod, the team can help identify it and point you to the right bushes. A clunk on take-off can also come from spring bushes, diff mounts or driveline joints, and looking at the vehicle as a whole helps make sure the right part gets replaced.

Find the Right Torque Rod Bushes with Formula 4x4

Use the vehicle search, then confirm which rod your vehicle uses and which end needs bushes. Consider polyurethane and check the product details for what is included.

Torque rods keep a live axle in check under load, and their bushes are found in our suspension bushes range.

If you are unsure what your 4WD needs, contact the Formula 4x4 team.