STORY OF THE DAY: A French Ferrari Succumbs to Its Gearbox

Robert Manzon and Louis Rosier shared the number 5 Ferrari 375 Plus at the 1954 24 Hours of Le Mans. Their race ended after 177 laps with gearbox failure, while the sister number 4 Ferrari of González and Trintignant won overall. The retirement left the French pairing unable to contribute directly to Ferrari’s championship points despite the model’s eventual victory.

The number 5 car formed part of Ferrari’s powerful assault on Jaguar, and its early pace placed another large V12 threat into the endurance contest. As rain and mechanical attrition reshaped the order, however, its gearbox failed before the decisive final phase. The contrast between two nominally similar Ferraris showed how small differences in load and circumstance determined survival.

The 375 Plus combined a tubular steel chassis with a front-mounted Lampredi V12 of almost five litres. Its high torque and streamlined open body made it exceptionally fast on the long straights, while a rear-mounted transaxle was used to improve weight distribution. The drivetrain nevertheless carried severe loads, and transmission durability was one of the car’s central endurance challenges.

Manzon and Rosier were French veterans. Manzon had built his reputation with Gordini in Grand Prix and sports-car racing, combining speed with a forceful character. Rosier was a driver and team owner who won the 1950 Le Mans race after spending nearly the entire distance at the wheel. Their experience made the retirement a mechanical defeat rather than a failure of endurance craft.