Individual Trailing Arms with Fitting Position Front Axle, Rear Axle for FPV FORCE 8 BF Sedan

A trailing arm is a suspension link that runs forwards from the axle or wheel hub to a mount on the chassis or body. On many 4WDs with a coil-sprung live rear axle, a pair of lower trailing arms, often working with upper links, holds the axle in position and controls its movement as the suspension cycles. Individual trailing arms are sold as a single left or right arm, which suits a one-sided repair after an impact, corrosion or a bush failure. Because the rear axle carries much of the weight when a 4WD is loaded or towing, sound trailing arms help keep it stable, square and predictable on and off road. Use the vehicle search to find individual trailing arms to suit your BF Sedan FORCE 8.

What Does a BF Sedan FORCE 8 Trailing Arm Do?

Locating the BF Sedan FORCE 8 Axle Fore and Aft

The main job of a trailing arm is to stop the axle moving forwards and backwards under acceleration and braking. On a live axle, drive torque tries to push the axle forwards and braking tries to pull it back. The trailing arms carry those forces into the chassis.

Controlling BF Sedan FORCE 8 Pinion Angle

On a live axle, the trailing arms, along with any upper links, also control how the axle rotates as it moves. That rotation sets the pinion angle, which is the angle at which the tailshaft meets the differential. A correct pinion angle helps the tailshaft universal joints run smoothly and can reduce driveline vibration.

Allowing Articulation

As one wheel climbs and the other drops, the trailing arms swing through an arc on their bushes. The bushes allow this articulation while absorbing vibration. Off road, they can be twisted well beyond their resting position, which is part of why they wear.

Why Buy a Single BF Sedan FORCE 8 Trailing Arm?

Damage on One Side

Lower trailing arms sit low under the rear of the vehicle, where they can contact rocks, ruts and logs. A single hard hit can bend one arm and leave the other untouched. Corrosion can also be worse on one side, particularly on vehicles used for beach driving or regular water crossings. Replacing only the affected arm can be a cost-effective repair.

When to Do Both Sides of Your BF Sedan FORCE 8

Many owners prefer to replace both arms at once. Fresh bushes on one side and worn bushes on the other can let the axle sit slightly out of square, which can affect tracking and tyre wear. If the vehicle has covered high kilometres or the opposite arm shows wear, doing both at once can avoid a second job.

What Types of Trailing Arms Are There for Your BF Sedan FORCE 8?

BF Sedan FORCE 8 Fixed Replacement Arms

These are built to the original arm's length and geometry. They suit a vehicle at or near standard ride height and are designed to restore the factory setup after damage or wear.

BF Sedan FORCE 8 Adjustable Arms

Adjustable trailing arms have a threaded section or adjustable mount that lets their length be changed. On a lifted 4WD, adjusting the arms can help set pinion angle and centre the axle in the wheel arch. They are generally used in pairs so both sides can be set evenly.

BF Sedan FORCE 8 Heavy-Duty Arms

Some aftermarket arms use thicker tube, stronger mounts or different bush designs to better resist bending and wear off road. These are often aimed at vehicles that see regular rock crawling or carry heavy loads.

Independent Rear Suspension

On some vehicles with independent rear suspension, the term trailing arm describes a link that locates the rear hub rather than a live axle. The principle of fore-aft location is similar, but the parts are different. Check the product details to confirm the arm suits your suspension layout.

What Are the Signs a BF Sedan FORCE 8 Trailing Arm Needs Attention?

Wear usually begins in the bushes, but the arm itself can also bend or corrode. Common signs include:

• Clunking from the rear when taking off, braking or crossing dips.
• Rear steer or a loose feel, where the back of the vehicle seems to move around on uneven roads.
• Driveline vibration that may point to a changed pinion angle.
• Uneven rear tyre wear.
• Cracked, split or squashed bushes, or bushes that have moved in their housings.
• Visible bending of an arm after contact with a rock or log.
• Heavy rust on the arm or around its mounts.

Panhard rod bushes, upper link bushes and spring seats can cause similar symptoms, so a full inspection of the rear end is worth doing before ordering parts.

BF Sedan FORCE 8 Lifted, Loaded and Towing Considerations

Lifted BF Sedan FORCE 8

Lifting a coil-sprung live rear axle changes the angle of the trailing arms. As the body rises, the axle can rotate and move slightly forwards or backwards. That can change pinion angle and move the axle off centre in the wheel arch. A small lift may not cause noticeable problems, but larger lifts often call for adjustable arms or other correction parts. A fixed replacement arm will generally keep the original geometry, so it will not correct these changes.

Loaded and Touring BF Sedan FORCE 8

Rear-mounted gear such as drawers, fridges, water tanks and spare wheel carriers adds steady load to the rear axle. That load increases the force through the trailing arm bushes, especially over corrugations. Loaded vehicles can benefit from more frequent rear suspension checks.

Towing With Your BF Sedan FORCE 8

Towing puts large fore-aft forces through the trailing arms, both when pulling away and when braking. Worn bushes can let the axle shift under these forces, which can show up as a clunk or a less settled feel with a trailer or caravan behind. Ball weight also adds load at the rear, so keeping the arms and bushes in good condition is worthwhile on any towing vehicle.

What Comes With an Individual BF Sedan FORCE 8 Trailing Arm?

What is supplied varies between arms and suppliers. Some arms come with bushes already fitted, while others are supplied bare. Mounting bolts, nuts and washers may or may not be included. Adjustable arms may come with lock nuts and fitting instructions. Check the product details before booking the job.

Should You Repair or Replace a BF Sedan FORCE 8 Trailing Arm?

When Repair Can Work

If the arm is straight and free of cracks, replacing worn bushes is often enough. Rubber and polyurethane bushes are generally available for common applications. Surface rust can often be cleaned back and treated before refitting.

When Replacement Makes More Sense

Replacing the arm is usually the better option when:

• The arm is bent or twisted.
• There are cracks in the arm, its welds or its mounts.
• Corrosion has weakened the metal.
• The bush housings are worn oval and new bushes will not seat properly.

A bent trailing arm should not be heated or straightened and refitted, as this can weaken it.

How Do You Choose the Right Arm for Your BF Sedan FORCE 8?

Left and Right

Left and right are generally described from the driver's seat, looking forward. On a right-hand drive vehicle, the left arm is on the passenger side and the right arm on the driver's side.

Upper or Lower, Front or Rear

Some suspensions use both upper and lower links, and these are different parts. Confirm the position and axle before ordering.

Existing BF Sedan FORCE 8 Modifications

Note any lift, spring change or other suspension work, as these can affect which arm suits your 4WD.

How Are BF Sedan FORCE 8 Trailing Arms Fitted?

Fitting a trailing arm involves supporting a heavy axle under load, so it is a job for a qualified technician. A typical process looks like this:

1. Support the vehicle on rated stands and support the axle so it cannot move when the arm is removed.
2. Remove the old arm, noting the position of any washers or spacers.
3. Fit the new arm with its bushes and hardware in the correct orientation. Set the length on adjustable arms as directed.
4. Tighten the bush bolts at ride height. Tightening with the axle hanging can twist the bushes and shorten their life.
5. Torque all fasteners to specification.
6. Check pinion angle where relevant, particularly on lifted vehicles.
7. Road test the vehicle and recheck the fasteners after the first few hundred kilometres. A wheel alignment is also worth doing on vehicles with independent rear suspension.

Find the Right BF Sedan FORCE 8 Trailing Arm with Formula 4x4

1. Use the vehicle search to show arms for your BF Sedan FORCE 8.
2. Confirm the side, position and axle.
3. Check the product details for bushes and hardware.
4. Consider whether the opposite arm needs replacing too.
5. Allow for any lift, rear load or towing in your choice.

If you are unsure what your BF Sedan FORCE 8 needs, contact the Formula 4x4 team.