(See "knocking" elsewhere on this forum) Noise originally suspected as "pinging" was immediately traced, by a second dealer, to rear portion of 6sp manual transmission. Car has 3800 miles, 700 since noise was first detected and brought to a Mazda dealer who, after 3 visits, declared the noise: "normal."

Mazda USA says tear it down to ID the cause/specific source. Question: Should I insist on a new tranny? Or is that being unreasonable? My concern is that debris has been circulating around the tranny for 3 mos. and 700++ miles causing accelerated wear on other parts - synchro clutches, gear teeth, bearings....

Probable gear or bearing manufacturing defect. Any other reports? I'll post more after the exploratory surgery.

 

Dealer #2 enlisted help from Mazda USA. Problem was described as "gear lash" caused by broken-down transmission fluid allegedly caused by excessive lugging??? by this, mechanically savvy driver, in 3000 miles. Fluid was changed; car driven; fluid still not clear; fluid changed again. Noise largely abated. Car pronounced sound, though I have my doubts. I will ensure car driven over 2200 RPM, and monitor for sound. Anybody have similar experience?

 

Another Mazda forum suggests that the noise, evident in my 6-sp '09 upon even light acceleration, particularly from about 2000 rpm, is endemic to the NC (post 2005) series. Evidently attributable to excessive gear lash in final drive. I suspect some transmissions more prone than others, some drivers more attuned than others. My plan: Document experience, trips to dealers, dealer "investigation/repair(?)" invoices; revisit status before warranty runs out or if amplitude or incidence increases detectably.

It is regrettable that Mazda USA does not acknowledge the issue and formulate a customer-oriented policy, such as: "Yes, we know of the issue; it varies with individual cars; if noise level indicates excessive transmission wear, we will replace transmission at no cost to owner, within warranty period."

 

I would like to collect data on the extent to which NC (2005+) owners with manual transmissions are experiencing "gear-lash" noise. If you read this post, please respond to me, privately, off-forum preferred, simply saying whether OR NOT you have experienced the noise described below. Thank you.

(I am aware of the reports elsewhere on web forums.)

Roger Bohl
rhbohl@gmail.com

Noise in question: A noise that occurs, after the transmission oil has gotten hot, that is audible upon acceleration, in any gear, from about 2,000 - 3,000 rpm. Sounds like wooden ***** or marbles in a wooden barrel. It appears to come from gear-lash vibration not damped by the transmission oil.

__ I have a ___-speed transmission and have such a noise (year?___)

__ I have a ___-speed transmission and do NOT have such a noise (year?___)

Additional feedback welcome.