Nissan FS5W71C / FS5R30A

Nissan's rear-drive five-speed manuals — the FS5W71C in the Maxima, Navara D22 and 300ZX, and the stronger FS5R30A behind the Patrol and the turbocharged 300ZX.

The letters are a size rather than a generation, and this is the practical point: the two appear in the same cars in the same years — a Z32 300ZX has one or the other depending on whether it is turbocharged — and they share no internals. A parts listing that says only 5-speed manual covers both.

The FS5W71C is a light-duty gearbox in vehicles people modify, and its failure follows: third-gear synchro first, grinding on a fast change, then the gear itself. A Navara or a Maxima that grinds into third under load is at the end of its rating rather than badly maintained.

The FS5R30A is a much stronger unit and its recurring complaint is noise rather than wear — a whine in the intermediate gears that is normal for the design.

Both take a specific gear oil and the Patrol's is not the Navara's; using a heavier oil than specified makes either notchy when cold and is regularly mistaken for synchro wear.