Supercars are exotic machines with expensive parts. Many of those parts are sourced from suppliers but can only be bought through the brands when it comes time for a repair. According to a Friday report from Road & Track, the Ford GT and Mercedes-AMG GT share a gearbox, but Ford charges a lot more for it if you have to replace it once you own the car.

Customers who need a new 7-speed dual-clutch gearbox for their Ford GT will have to pay almost twice as much as AMG GT buyers. The Getrag 7DCL750 dual-clutch transmission the GT runs costs $32,324, which includes a $5,000 core charge if the customer doesn't have a unit to return. Customers who do have a transmission to exchange pay $27,624.

2019 Mercedes-AMG GT S Roadster

2019 Mercedes-AMG GT S Roadster

Meanwhile, the exact same transmission with identical gear ratios costs $14,940 from Mercedes-AMG. Online discount retailers sell the transmission even cheaper for $13,446. The report claimed similar discount retailers also sell the GT's transmission at a 14.5-percent discount (for a $28,318), but Ford likely would block the sale unless the buyer already owns a GT or works with a GT concierge.

Why does Ford's transmission cost so much more? Motor Authority reached out to Ford for comment on the gearbox's price and a spokesman said, "The Ford GT is the pinnacle of Ford Performance innovation. Parts replacement costs reflect their limited production volume and integrated, race-bred calibration and performance."

Ford and Mercedes-AMG aren't the only manufacturers to source the 7DCL750 dual-clutch transmission, either. Ferrari also uses the gearbox in the 458 and California. However, the gear ratios are vastly different from those used in the AMG GT and Ford GT. Although the housing and parts are all very similar, the Ferrari models sport different final drive ratios and differ in 5th, 6th, and 7th gears. Yet, Ferrari also sells the transmission cheaper than Ford; a 458 transmission costs $22,186.

Editor's note: This story has been updated with a statement from Ford.