Aisin AY6

Aisin's six-speed manual — behind the V6 Camaro and the Holden Commodore and Ute.

It is the gearbox fitted where the Tremec goes behind the V8, which is the distinction worth making: a Camaro or a Commodore described as having a six-speed manual may have this or a TR-6060, and they are entirely different gearboxes with different parts and different ratings.

It is a light-duty unit behind engines people modify, and its failure follows from that: the third-gear synchro first, then the gear. A gearbox that grinds into third under load is at the end of its rating, which is the same story as the Tremec T-5 and the Nissan FS5W71C.

Shift feel complaints are usually the linkage — the bushings and the shifter's own base — and cost a fraction of anything inside.

Its clutch hydraulics are inside the bellhousing on most applications, so a leaking slave cylinder is a cheap part behind an expensive job: replace it whenever the gearbox is out.