Ferrari say the failure that led to Charles Leclerc’s retirement before the start of the Monaco Grand Prix was caused by his crash in qualifying.
The team were not initially sure what led to the left-hand driveshaft hub failure that caused Leclerc to lose drive after he left the pits pre-race.
But Monday’s investigation at their Maranello factory confirmed it was a consequence of Saturday’s accident.
Ferrari say they will update their procedures for future races.
The failure cost Leclerc the chance to start his home race from pole position, and cost the team – who have not been able to compete with title contenders Mercedes and Red Bull at other races this season – what could be their only chance to win a Grand Prix this year.
The part in question is not normally one that would be inspected after such an accident, a spokeswoman said.
And the failure was also unexpected because it was on the opposite side of the car from the one that hit the barrier on the exit of the Swimming Pool section of the track.
Leclerc’s crash inadvertently secured his pole position because it removed the possibility of other drivers beating the fastest time he had set on the first of two runs for each driver in the final qualifying session.
Race officials conducted a brief investigation into the incident but concluded it was an honest mistake caused by trying too hard, and there was no evidence he had crashed deliberately.
Ferrari’s initial concerns after the accident were for the gearbox. If that had needed changing, Leclerc would have been given an automatic five-place grid penalty and would have had to start from sixth place.
Teams can ask governing body the FIA for permission to change damaged parts after a crash but they did not request a change of the driveshaft or its hubs.
They did not see a fault with the driveshaft, and the hubs were not inspected as they would not normally be expected to fail in such a situation, the team said.
However, they admit the incident has been “a lesson learned” and the team will instigate new procedures in the future to try to avoid such a situation arising again.
The part did not immediately fail when Leclerc started driving the car, but the 23-year-old lost drive in the tunnel halfway around the lap on his way to the grid.
