Watts Link Bushes with Fitting Position Front Axle, Rear Axle for FORD FAIRLANE ZK, ZL

A Watts link is a three-piece linkage that holds a solid axle centred under the vehicle while it moves up and down. Where a panhard rod uses a single bar across the vehicle, a Watts link uses two shorter rods joined to a pivoting centre piece, so the axle stays closer to centre through its whole travel. It is an uncommon setup on 4WDs, but where it is used, every sideways force on the axle passes through its bushes. When those bushes wear, the rear axle shifts on corners and bumps, and the back of the vehicle starts to feel as though it has a mind of its own. Use the vehicle search to find Watts link bushes to suit your ZK, ZL FAIRLANE.

What a ZK, ZL FAIRLANE Watts Link Does

A solid axle needs locating in two directions. Trailing arms or links stop it moving fore and aft. Something else has to stop it moving sideways.

A panhard rod is the most common answer on 4WDs. It runs across the vehicle from the axle to the chassis. Because it swings in an arc, the axle moves slightly sideways as it rises and falls.

A Watts link solves that with three parts. A centre piece, often called the bell crank or propeller, pivots on the axle or the chassis. Two rods run outward from each end of it to the opposite side of the vehicle. As the axle moves up and down, the two rods swing in opposite arcs, and the centre piece rotates to take up the difference. The result is that the axle moves close to straight up and down, with much less sideways shift than a single panhard rod allows.

ZK, ZL FAIRLANE Watts Link or Panhard Rod?

Both do the same basic job. A Watts link generally keeps the axle more centred through its travel, which helps stability on rough roads and over long suspension travel. A panhard rod is simpler, uses fewer parts and fewer bushes, and is far more common on 4WDs.

Which 4WDs Use a Watts Link?

Watts links are uncommon on 4WDs. They are more often found on some passenger cars and on certain four-wheel-drive models with a coil sprung solid rear axle, including some Land Rover models. Most 4WDs with a coil sprung rear use a panhard rod instead, and leaf sprung bakkies are located sideways by the springs themselves.

A quick look under the rear will show which you have. A Watts link has a pivoting centre piece, usually mounted on the axle housing, with a rod running from each end out to the chassis. The vehicle search shows which parts suit your vehicle.

Where ZK, ZL FAIRLANE Watts Link Bushes Sit

A Watts link has more bushes than a panhard rod, and all of them matter.

Centre pivot bush. The centre piece rotates on a pivot, usually with a large bush or bearing at its centre. This bush carries the combined load from both rods.

Rod end bushes. Each of the two rods has a bush at each end: one where it meets the centre piece, and one where it mounts to the chassis or body.

That means up to five bush positions per Watts link. Kits may cover the centre pivot, the rod ends or all of them, so the product details are the place to check.

Signs Your ZK, ZL FAIRLANE Watts Link Bushes Are Worn

A clunk or knock from the rear when cornering, crossing ruts at an angle or changing direction is a common sign. The axle shifts sideways in worn bushes until the slack is taken up.

A vague or loose rear end is another. The vehicle can feel as though the rear is steering itself, wander on uneven roads or feel less settled in crosswinds.

Uneven rear tyre wear can follow if the axle shifts off centre under load.

On inspection, look for cracked, split or squashed bushes, especially at the centre pivot, rubber pushed out of the housing, or movement when the centre piece or rods are levered.

Panhard rod bushes on vehicles that have them, trailing arm bushes and wheel bearings can cause similar symptoms, so a full rear end inspection is worth doing first.

ZK, ZL FAIRLANE Lifted, Loaded and Towing Considerations

Lifted ZK, ZL FAIRLANE

A lift changes the angle of the Watts link rods, just as it changes the angle of a panhard rod. Because of its geometry, a Watts link generally keeps the axle closer to centre after a lift than a panhard rod does, but the rods and centre piece still sit at different angles and the bushes carry a different load. Bolts should be tightened at the new ride height so the bushes are not preloaded in a twisted position.

ZK, ZL FAIRLANE Heavy Rear Loads

Touring gear, drawers and water in the rear add weight right over the axle. That increases the sideways force through the Watts link in every corner, and can speed up bush wear.

Towing With Your ZK, ZL FAIRLANE

A trailer or caravan adds side forces at the rear, particularly in crosswinds and when changing lanes. The Watts link takes those forces, and worn bushes can let the axle move under them, which makes the vehicle feel less stable with a load behind.

ZK, ZL FAIRLANE Rough Roads and Corrugations

Corrugations and rough tracks put constant small cycles through every Watts link bush, and the centre pivot works on every one of them. Dust, mud and water add to the wear.

Rubber or Polyurethane ZK, ZL FAIRLANE Watts Link Bushes?

Factory Watts link bushes are usually rubber. Rubber isolates noise and vibration but deflects under side load, and as it ages it softens and cracks, letting the axle move further sideways.

Polyurethane bushes are generally firmer and hold the linkage more precisely, which tends to reduce rear axle shift and clunks. They may transmit a little more vibration, and some designs need grease to stay quiet.

What Comes in a ZK, ZL FAIRLANE Watts Link Bush Kit

Kits vary by vehicle. Some cover the centre pivot only, some cover the rod ends, and some cover the whole linkage. Sleeves, washers and lubricant may or may not be supplied. Check the product details for which positions the kit covers and what is included.

Replace the ZK, ZL FAIRLANE Bushes or the Linkage?

New bushes are the fix when the rods and centre piece are straight, their housings are still round and the mounts are sound.

Parts need replacing when a rod is bent from an impact, the centre piece or its pivot is damaged, or corrosion has weakened the mounts. Because the Watts link sits low under the rear axle on many vehicles, it can be hit by rocks or logs off road, so check for damage as well as wear.

Fitting ZK, ZL FAIRLANE Watts Link Bushes

Replacing Watts link bushes is a job for a qualified technician. The vehicle is supported on rated stands with the axle supported. The rods and centre piece are removed as needed, old bushes are pressed out, and the housings are cleaned and checked. New bushes are fitted with any lubricant supplied.

The linkage is refitted and the bolts are tightened with the vehicle at ride height, and all fasteners are torqued to specification. A road test through corners and over rough ground confirms the clunk has gone and the rear feels settled.

How Formula 4x4 Can Help With Your ZK, ZL FAIRLANE

Formula 4x4 works across the whole 4WD suspension, which helps on a setup that only some vehicles use. If you are not sure whether your vehicle has a Watts link or a panhard rod, the team can help identify it and point you to the right bushes. A loose rear end can come from several links, and looking at the whole rear suspension helps make sure the right part gets replaced.

Find the Right ZK, ZL FAIRLANE Watts Link Bushes with Formula 4x4

Use the vehicle search, then confirm your ZK, ZL FAIRLANE has a Watts link rather than a panhard rod. Identify which positions need bushes, decide between rubber and polyurethane, and allow for any lift, load or towing. Check the product details for what is included.

If you are unsure what your ZK, ZL FAIRLANE needs, contact the Formula 4x4 team.