Front Lower Curved Suspension Arms | Discovery & Range Rover

Models Affected:

A knocking or banging noise from the front suspension when driving over poor road surfaces or turning sharply is a common complaint on the Discovery 5 and the full-size Range Rover models. One of the most frequent causes is wear in the front lower curved suspension arms, particularly on the large bush end, and the ball joint if the grease escapes and the joint runs dry.

This guide outlines the common symptoms of front lower suspension arm wear, how to confirm the issue, and the correct procedure for suspension arm replacement.

Symptoms of Worn Front Suspension Arms

  • Knocking or banging from the front suspension when driving over potholes, speed bumps, or uneven surfaces

  • Noise or vibration when turning side to side at low speeds

  • Dry or split ball joint boots, or visible bush degradation

  • In some cases, vague steering or poor road feedback

  • A distinct thud or clunk under sudden braking as the load is transferred to the bushings

Diagnosis & Cause

Commonly referred to as the “banana arm” due to its curved shape, each front curved lower arm has:

  • A large rubber bush on one end that connects to the subframe/chassis

  • A ball joint at the other end that connects to the hub knuckle.

The large bush can perish or deform over time, especially under the weight and suspension movement of heavier vehicles like the Discovery and Range Rover models. The ball joint can also run dry if the protective boot splits and grease escapes, leading to metal-on-metal knocking and accelerated wear, eventually causing play in the joint.

This wear is common after 50,000–80,000 miles, especially on vehicles used in harsh road conditions or off-road where the joints will be articulating more than average and slowly pull themselves apart over time.

How is the problem solved

Although it is not a technically complex job, replacement of the front lower suspension arms is made more difficult because of the steel ball joint bolt seizing inside the alloy hub knuckle due to galvanic corrosion from the dissimilar metals.

PLEASE NOTE: We strongly recommend using the special JLR ball joint separator tool to avoid damaging the surrounding components

Step-by-step summary:

  1. Raise the vehicle and remove the front wheel
  2. Remove the driveshaft to avoid damaging the CV boot during the job
  3. Loosen (but do not fully remove) the ball joint nut
  4. Use the JLR ball joint separator tool to release the ball joint from the alloy knuckle
  5. Remove and discard the old ball joint nut
  6. Undo and remove the M14 x 148mm bolt and nut from the front arm bushing
  7. Prise out and remove the curved arm
  8. Fit the new arm with new hardware (nuts and bolts)
  9. Refit the driveshaft and reinstall the front wheel

PLEASE NOTE: The lower arm bolt is a stretch bolt that will require heavy duty tools and significant force to loosen and torque up upon replacement. The original hardware must be discarded as it will be unfit for purpose after removal.

Torque settings:

M14 bolt (through front bush)

  • Stage 1: 100 Nm
  • Stage 2: +360° (torque-to-yield)

Lower control arm nut (ball joint)

  • Lower control arm nut (ball joint): 290 Nm

The following parts are required for the replacement of both front suspension arms:

  • LR148059 – Front Lower Curved Arm – Right Hand
  • LR148060 – Front Lower Curved Arm – Left Hand
  • LR097372 – M14 x 148mm Bolt
  • LR188116 – M14 Nut
  • LR034221 – M16 Flanged Ball Joint Nut

Estimated Repair Costs

This estimate is for the replacement of new front lower arms (both sides), new fixings, and labour to remove, replace, and torque components to spec. Followed by a four-wheel alignment. VAT is also included. Please contact us with your registration number for a personalised estimate.

Frequently Asked Questions

If your suspension arm is not severely worn, you can drive around for a while whilst waiting for a repair. However, if the arm is badly worn, you will likely observe accelerated and uneven tyre wear and unpredictable handling characteristics.

Yes. Replacing your suspension arms will affect the suspension geometry. We recommend a full four-wheel alignment after fitting and this has been priced into our estimate.

This process is called Galvanic Corrosion, where two dissimilar metals (It’s a steel bolt going into an alloy hub) are in contact and are exposed to moisture from the environment. This causes an electrochemical reaction where the two items seize together. Proper tools, penetrant and extreme patience are often essential to avoid damage.

We recommend it. If one side has failed due to wear, the opposite side is usually not far behind, and replacing both can save on labour and alignment costs later.

Need help fixing this issue?

Call us on 01772 368807 or get in touch online to book a repair or get friendly advice.