Incorrect differential oil

The consumer’s issue:

“I bought a high performance sports coupé with a service plan and warranty, and within a week of buying the car, it was suffering from gear change issues. I took the vehicle to an independent specialist and they resolved the issue, meaning the transmission ran fine from then on. I returned to have the car serviced by the seller six months and a year after I bought the car, where the engine oil and differential oil were changed at the first service, with just the engine oil changed at the second one.

After the second service, the vehicle started to behave differently. I took it to a third-party garage for investigation. They found that whoever replaced the oil in the differential with the wrong viscosity was directly responsible for the damage caused to the front differential assembly and the four-wheel-drive (clutch) assembly. This was because the increased resistance of the front driveline (front differential assembly) was causing the clutch plates to overheat and burn.

The garage concluded that it would cost £5,000 to repair the vehicle, and to resolve my complaint, I am looking for the business that serviced my car to cover the full cost of the remedial work needed so that I am not left out of pocket.”

The accredited business’ response:

  • We did complete a service on the vehicle as stated by the consumer.
  • We have spoken to the manufacturer since, and they confirmed that the correct differential oil had been ordered and used on the customer’s vehicle.
  • Therefore, in light of the above, we are satisfied that our service team has acted correctly, and are not responsible for covering the cost of any remedial work.

The adjudication outcome:

  • The Motor Ombudsman adjudicator explained that it was up to the customer to show that the accredited business did in fact use the incorrect oil for the front differential assembly, and that this subsequently caused the issues with their vehicle.
  • The adjudicator examined the service invoices provided. He noticed that only three units of oil for the rear differential was ordered by the accredited business.
  • However, the adjudicator noted the advice from the manufacturer stated that a different oil was needed for the front and rear differential.
  • As the invoice showed three units of the same differential oil had been used and ordered, the adjudicator found that, on balance, the incorrect oil had been used, which subsequently led to the damage reported by the customer.
  • As such, the adjudicator upheld the consumer’s complaint, and recommended that the business covered the full costs of repair (i.e. the £5,000 which had been quoted).
  • Although the consumer agreed with the outcome, the accredited business did not accept the adjudicator’s decision despite reasons being requested for this, meaning the case therefore passed to an ombudsman for a final decision.

The ombudsman’s final decision:

  •  The ombudsman noted that the report from the third-party garage provided by the consumer clearly stated that the use of the incorrect oil caused damage to the front differential assembly and the four-wheel-drive (clutch) assembly.
  • The document also highlighted that the front differential requires oil of a specific specification. To this end, there was no reference in the repairer’s defence to a different oil being used or required in the front differential of the consumer’s vehicle.
  • The ombudsman said that he was also aware that one of the documents from the independent garage stated that the wrong oil was also used in the rear differential. However, it was not clear whether the incorrect oil was actually used in the rear differential, as the numbers on the oil seemed to match the advice provided by the manufacturer.
  • As a result, no fault was actually confirmed in the rear differential. In fact, if the rear differential oil had been incorrect, the ombudsman would have expected to see some report of excess wear or damage to the rear differential. However, none was noted in the independent report, meaning the rear differential oil was correct.
  • Based on the evidence presented, the ombudsman was satisfied that the business being complained about had used the incorrect oil, and was the cause of the failure of the four-wheel-drive (clutch) assembly and the front differential assembly.
  • In summary, like the adjudicator, the ombudsman upheld the complaint in the consumer’s favour.

Conclusion:

  • The consumer accepted the ombudsman’s decision, and the accredited business was legally obligated to reimburse them for the full cost of repair upon the receipt of a valid invoice.