Charles Leclerc’s retirement before the start of the Monaco Grand Prix was due to a cracked left-rear wheel hub as a result of his accident in qualifying on Saturday, Ferrari has discovered.
The crack – on the opposite side to the impact with the wall at the Swimming Pool exit – was not visible in the garage as the checks were made.
When Leclerc left for his install lap before the race on Sunday the car appeared fine after the previous day’s incident, until he went to accelerate from the hairpin at which point the hub failed and in so doing damaged the driveshaft, leaving the pole position-setting car with no drive to the left-hand side.
Ferrari has confirmed it will be reviewing its procedures in light of the incident.
It had initially been unsure whether the driveshaft problem might have been completely unrelated to the qualifying crash, given that it occurred on the opposite side of the car, but said on Sunday night that its biggest priority was working out whether it could have identified the problem sooner.