Mazda M526 / AZ6 / B2C2-B

The manual gearboxes of the MX-5 and the Mazda3 — the five-speed M526, the Aisin AZ6 six-speed, and the B2C2-B transaxle.

⚑ The MX-5's six-speed is Aisin's, and its five-speed is Mazda's. They are different gearboxes with different ratios, different fluid and different failure patterns, in the same car in the same year. Which one a car has is the first question, and the badge does not say.

The MX-5's shift quality is the car's defining feature and owners notice degradation quickly — which is why so many reports exist for what is, mechanically, a very reliable gearbox.

Almost all of them are fluid. Mazda specifies its own gear oil and the aftermarket alternatives change the feel; a notchy second-gear change when cold is the standing symptom and the standing cause.

The B2C2-B is a transverse transaxle for the Mazda3 and shares nothing with the rear-drive boxes above it, despite arriving in the same catalogue rows.