What is a driveshaft hub and how was it affected in Leclerc crash?

Charles Leclerc's crash during Formula 1's Monaco qualifying session, which Ferrari now believes caused the broken driveshaft that rendered him unable to take pole, still leaves unanswered questions.

What is a driveshaft hub and how was it affected in Leclerc crash?

Ferrari reported that the left driveshaft hub was broken on Leclerc's car, which the team only discovered following Leclerc's reconnaissance lap to the grid as the Monegasque driver struggled with drive.

This had not been part of Ferrari's pre-race checks, and so the underlying issue remained undiscovered until the team finally produced a full autopsy of the gearbox and associated components following Leclerc's inability to start the race.

The driveshaft is the part of the car that translates the mechanical effort produced by the engine and power unit components into drive for the rear wheels. This is done so via the gearbox and differential.

The differential connects to the driveshaft hub; the gearbox produces the right amount of drive with regards to rpm and torque, and then the differential offers the driveshafts the chance to move at different rotational velocities when cornering.

As the hub is the part of the driveshaft that delivers the motion to the rear wheels, any damage would ensure that the drive from the powertrain and drivetrain is severely impaired.

Leclerc felt this on his run to the grid, forcing him to take to the pits - but it proved to be an issue that could not be fixed in time to join the race.

The driveshaft hub is allowed to move with minimal friction via the use of bearings, and any damage here would introduce friction into the system which means that the acceleration would not be smooth.

Ferrari SF21 suspension detail

Ferrari SF21 suspension detail

Photo by: Giorgio Piola

This can also cause damage to the driveshaft as it would begin to flex under the increased vibrations produced. Although Leclerc's car would be incredibly difficult to drive, it would also strongly risk failing.

One question unanswered was how the left driveshaft hub was damaged when the impact affected the right-hand side of Leclerc's SF21.

The side-on nature of the impact will have sent a shock down the car in response to the crash, and therefore it's entirely plausible that the shock via the differential provided a reactive impact to the driveshaft hub - although it is unclear which part of the hub was damaged.

Read Also:

There are a number of joints situated within the driveshaft too to allow it to sit at a slight angle and still provide the correct drive to the wheels, and these are rarely designed to take an impact in that direction and remain in one piece.

Damage to the driveshaft hub escaped Ferrari's notice as it did not expect the left-hand side of the car to be damaged, but replacing the gearbox may have brought the issue to light - even if it planned to install the same driveshaft - as a technician would have had a chance to inspect the component.

Ferrari has since admitted that it will change its internal processes in the event of a crash and extend its due diligence to any other parts that could be directly affected.

shares
comments

Related video

Max Mosley in his own words
Previous article

Max Mosley in his own words

Next article

Obituary: Max Mosley, 1940-2021

Obituary: Max Mosley, 1940-2021
Load comments
How F1 teams and personnel react in pressurised situations Prime

How F1 teams and personnel react in pressurised situations

OPINION: The pressure is firmly on Red Bull and Mercedes as Formula 1 2021 embarks on its final double-header. How the respective teams deal with that will be a crucial factor in deciding the outcome of the drivers' and constructors' championships, as Motorsport.com's technical consultant and ex-McLaren F1 engineer Tim Wright explains.

How getting sacked from Benetton made Mercedes' Allison Prime

How getting sacked from Benetton made Mercedes' Allison

He’s had a hand in world championship-winning Formula 1 cars for Benetton, Renault and Mercedes, and was also a cog in the Schumacher-Ferrari axis. Having recently ‘moved upstairs’ as Mercedes chief technical officer, James Allison tells Stuart Codling about his career path and why being axed by Benetton was one of the best things that ever happened to him.

Formula 1
Nov 28, 2021
The remarkable qualities that propelled Kubica’s F1 comeback Prime

The remarkable qualities that propelled Kubica’s F1 comeback

It’s easy to look at Robert Kubica’s second Formula 1 career and feel a sense of sadness that he didn’t reach the heights for which he seemed destined. But as Ben Anderson discovered, performance and results are almost meaningless in this context – something more fundamental and incredible happened…

Formula 1
Nov 27, 2021
The humbling changes Ricciardo made to deliver for McLaren Prime

The humbling changes Ricciardo made to deliver for McLaren

From being lapped by his own teammate in Monaco to winning at Monza, it’s been a tumultuous first season at McLaren for Daniel Ricciardo. But, as he tells STUART CODLING, there’s more to the story of his turnaround than having a lovely summer holiday during Formula 1's summer break...

Formula 1
Nov 26, 2021
The potential benefits of losing the F1 constructors' title Prime

The potential benefits of losing the F1 constructors' title

As the battle continues to rage over the F1 2021 drivers' championship, teams up and down the grid are turning their attentions to the prize money attributed to each position in the constructors' standings. But F1's sliding scale rules governing wind tunnel and CFD use will soften the blow for those who miss out on the top places

Formula 1
Nov 25, 2021
The invisible enemy that's made Hamilton's title charge tougher Prime

The invisible enemy that's made Hamilton's title charge tougher

After winning his past few Formula 1 titles as a canter, Lewis Hamilton currently trails Max Verstappen by eight points heading into the final double-header of 2021. Although Red Bull has been his biggest on-track challenge, Hamilton feels that he has just as much to grapple with away from the circuit

Formula 1
Nov 24, 2021
Why F1's inconvenient penalties have to stay Prime

Why F1's inconvenient penalties have to stay

OPINION: Quibbles over the length of time taken by Formula 1's stewards over decisions are entirely valid. But however inconvenient it is, there can be no questioning the importance of having clearly defined rules that everyone understands and can stick to. Recent events have shown that ambiguity could have big consequences

Formula 1
Nov 23, 2021
The mistakes Red Bull cannot afford to repeat in F1 2021's title fight climax Prime

The mistakes Red Bull cannot afford to repeat in F1 2021's title fight climax

OPINION: Red Bull has had Formula 1’s fastest package for most of 2021, but in several of the title run-in events it has wasted the RB16B’s potential. It cannot afford to do so again with Lewis Hamilton motoring back towards Max Verstappen in the drivers’ standings with two rounds remaining

Formula 1
Nov 23, 2021