Manual gearbox: 2nd and 3rd gear

The first ND's six-speed manual gearbox had a run of failures, mostly in 2nd and 3rd gear, and Mazda changed the gears for cars built from September 2016. This page says what Mazda's bulletin says and what owners reported. It is not a repair guide.

How to read it. Mazda bulletins are summarised in my own words from the documents I read on 1 October 2026; owner accounts are from Miata.net forum threads, dated below, and are individual experience. There are no prices on this page.

Mazda's bulletin

Mazda North American Operations service bulletin 05-007/16, "Grinding or Unusual Noise from Manual Transmission when Driving in 2nd and/or 3rd Gear", last issued 7 December 2016, is in Miata.net's collection (PDF). I read page 1. In my words:

• Cars covered: 2016-2017 MX-5 with VINs lower than JM1ND****H*121392, produced before 6 September 2016.
• Symptoms: a grinding noise when shifting from 1st to 2nd or 2nd to 3rd; being unable to shift into 2nd or 3rd while the other gears shift normally; or an unusual noise from the transmission in neutral with the engine idling.
• Cause as Mazda states it: damage to the 2nd and 3rd gears if the car was driven with rapid acceleration and deceleration and frequent shift changes. The configuration of those gears was changed to increase rigidity. Transmissions with serial number 6TJ0701679 or higher are the modified ones.
• The Miata.net list shows a related Mazda Japan document, R083/16B (March 2017), on the same noise, which I did not open.

Bulletins are for dealers, not recalls, and customers should not assume one applies to their car; a Mazda dealer can say whether it does.

What owners say

From "The Official -Facts Only- ND Transmission Failure Thread" (May 2016 to 2017; I read its first part):

• The failures. The thread's author described the failure as a transmission that seized or lost the ability to shift, often with little warning, with major damage to the gears, most often 2nd. Owners reported failures at as little as 400 miles up to over 20,000, on road cars and on cars driven hard at autocross and track days; the first report was in January 2016.
• Warranty. Many owners said Mazda replaced the whole transmission under warranty, sometimes within days, though one first had a claim denied for "abuse" and later reversed. One owner's replacement failed too. A Mazda North America warranty contact told the thread's author that Mazda had a 5-year, 60,000-mile transmission warranty and would probably issue a bulletin if needed. He said the cause was under investigation at that time. The thread's author said he knew of no failure that had not been covered by warranty, except one owner who paid himself for a race-use car.
• The change. A poster who follows Mazda parts catalogs listed gear part numbers that changed in 2016 (first, second and third gears, countershaft, reverse), with new ones from 5-6 September 2016, and said Mazda renews the whole transmission rather than the gears. The assembly part number did not change; a poster said the date code on the transmission's label shows the build date. Those are one poster's transcriptions of the parts catalog, not a Mazda document I read.
• Cause. Posters speculated about metallurgy or gear processing; one who works in gear manufacturing said the photos looked like fatigue and a process problem, not a design flaw. Another said Mazda attributed it to gear metallurgy. These are speculation by posters.
• Not a recall. A poster stressed that it is not a safety recall.

Later cars

Search results show owners of 2022 and 2023 NDs reporting 3rd gear grinds and replacements under warranty; I did not read those threads, so treat this as a lead.

Not covered yet

• Mazda's current warranty terms; ask a dealer or check your warranty booklet.
• Aftermarket transmission strengthening and who sells it. Grassroots Motorsports has an article on it; I did not open it.

© 2026 Fischer Interactive LLC. Written for the Ref Sensor app's Miata users. The seller's page is the authority.