sylvaman Posted March 30, 2020 Share Posted March 30, 2020 Hi All, Does anyone else get a chattering noise (prob not best description ) on the overrun, No throttle or very light throttle load, at varying speeds ?This is on a late model ; Sigma engine/Mazda gearbox i believe ? 310S. Very low mileage (1500)I am just about to check the gearbox oil level .Which i think is on the nearside , 14mm square plug ? If someone could verifiy this before i undo, and something falls off inside the gearbox....oops.Thanks Chaps. Link to comment Share on other sites More sharing options...
Member Jonathan Kay Posted March 30, 2020 Member Share Posted March 30, 2020 "Filling the Mazda 5 Speed Gearbox"Jonathan Link to comment Share on other sites More sharing options...
Member Jonathan Kay Posted March 30, 2020 Member Share Posted March 30, 2020 Does anyone else get a chattering noise (prob not best description ) on the overrun, No throttle or very light throttle load, at varying speeds ?In all gears? And neutral?Jonathan Link to comment Share on other sites More sharing options...
sylvaman Posted March 30, 2020 Author Share Posted March 30, 2020 Thanks J, for that link....on Mazda level plug.......You are a Star ! .Yes i would say in all gears , but as you spend some time when cruising, in the higher gears,(exhaust note lower) when you really notice it. There is a noise similar in neutral, (tick over) which you can eliminate by pressing clutch fully. Which would suggest Thrust bearing. But i have not heard a thrust bearing that makes that noise ......Yet ! i have owned several Mx5's includin a Mk3 for 7 years, which i believe this box is from ? And they were quiet , but then i suppose they had more insulation/ rubber mounting.Plus my Se7en is full of newness , at just over year old....but then...built by CC. Link to comment Share on other sites More sharing options...
Member Jonathan Kay Posted March 30, 2020 Member Share Posted March 30, 2020 i have owned several Mx5's includin a Mk3 for 7 years, which i believe this box is from ?Click the image for the whole fascinating LF article.Jonathan Link to comment Share on other sites More sharing options...
sjl1 Posted March 30, 2020 Share Posted March 30, 2020 Yes, they do rattle on overrun, worst in 4th gear i think, have driven 3 that all did/do it Link to comment Share on other sites More sharing options...
sylvaman Posted March 30, 2020 Author Share Posted March 30, 2020 You are J , that is a Brilliant read . Thank you for that , I have saved the article. Incidentally, I now own a Mk4 ND2 . A much lighter car than the mk3 , (similar to mk1) . Link to comment Share on other sites More sharing options...
sylvaman Posted March 30, 2020 Author Share Posted March 30, 2020 Thats Interesting sjl1. 4 th gears gear, certainly ties up. Nothing to worry about then ? Do you have a mazda gearbox car now or Ford ? Link to comment Share on other sites More sharing options...
kiloromeo Posted March 30, 2020 Share Posted March 30, 2020 My 2019 270S, Sigma/Mazda box, has a similar 'chatter' when I lift off the throttle to slow down. It is very noisy at for example 50mph in 4th gear. I have had a funny look from a couple of passengers who know I've assembled it and think I've left something off!Also when sitting stationary in neutral, a clutch/gearbox whine, but as soon as I depress the clutch pedal to engage a gear, the whine stops.I was told by Caterham that both noises are normal, but I suspect that not all cars do it.I'd be interested to know what you find your gearbox oil level to be.And if anyone else has resolved either of these noises? Link to comment Share on other sites More sharing options...
sylvaman Posted March 30, 2020 Author Share Posted March 30, 2020 Well that is a relief (if you know what i mean) that we both have exactly the same noises, same newish cars, kiloromeo. I will check the level and keep you informed.and in the meantime; as you say; Has anyone out there solved these noises ? Link to comment Share on other sites More sharing options...
sylvaman Posted March 30, 2020 Author Share Posted March 30, 2020 Just a thought , perhaps the "turret" level beneath the gear lever needs checking too, in case its low or dry (as in Jonathans link). As this is a separate fill from the main Mazda gearbox. Did you fill yours when you built it , kiloromeo ? Link to comment Share on other sites More sharing options...
7 wonders of the world Posted March 30, 2020 Share Posted March 30, 2020 The turret lubes the linkage, the chatter is more likely the laygear when the car is on a neutral throttle which allows a chatter, it could be down to marginal mapping on the engine leading to a little driveline shunt, or a subtle difference in running clearances as the gearboxes are rear cased as the OE Mazda runs with the Duratec with a 10 degree cant. Link to comment Share on other sites More sharing options...
sylvaman Posted March 30, 2020 Author Share Posted March 30, 2020 Wow! Good technical explanation. Thank you. Sounds all very likely; as i saw when underneath that it is a Caterham marked gearbox casing, so the tolerances could well be different from OE Japanese fitment. Link to comment Share on other sites More sharing options...
Wrightpayne Posted March 31, 2020 Share Posted March 31, 2020 I'm surprised SPC haven't developed a fix along with a lightweight semi-helical gear kit and some secret new tolerances. Link to comment Share on other sites More sharing options...
sylvaman Posted April 1, 2020 Author Share Posted April 1, 2020 Gearbox oil level checked , and all ok. It is a square plug, Which can be undone from underneath with a 14mm open ended spanner or from up top, or through passenger side, tunnel , if you peel back the carpet you will see a large round blanking grommet. Remove (cut out insulation material if you have it) 17mm bi-hexagon socket fits ( Halfords Advanced ,of course )So it sounds like something we Mx5 gear boxed cars, have to live with for the time being. Link to comment Share on other sites More sharing options...
kiloromeo Posted April 1, 2020 Share Posted April 1, 2020 Did you fill yours when you built it , kiloromeo ?The gearbox came prefilled. Link to comment Share on other sites More sharing options...
sylvaman Posted April 1, 2020 Author Share Posted April 1, 2020 Wow....They do think of everything Link to comment Share on other sites More sharing options...
sjl1 Posted April 2, 2020 Share Posted April 2, 2020 Its worse on sigma engined cars than Duratecs and probably related to fuelling and lightweight flywheels. Sigma engine cars are more prone to kangarooing and i suspect this has a lot to do with it, i think RnR mentioned that to me. Strangely louder from passenger seat than drivers seat also? Just wear earplugs :-) Link to comment Share on other sites More sharing options...
7 wonders of the world Posted April 2, 2020 Share Posted April 2, 2020 The kangarooing is driveline shunt and most if not all can be eliminated by subtle mapping tweaks. Link to comment Share on other sites More sharing options...
StevehS3 Posted May 28, 2023 Share Posted May 28, 2023 I noticeably reduced (but not eliminated) the chatter on overrun, most noticeable in 4th, by two changes. Firstly changing the gearbox oil to Redline MTL. This eliminated the notchy feel to the Mazda box, although strangely it seemed to take a few hundred miles and just got better and better. The other was a very slight opening of the throttle stop which I think mine needed anyway. The engine braking deceleration was quite harsh in my 310R prior to this and it also noticeably reduced the gearbox chatter on overrun. It is much more pleasant to drive with these two changes. Link to comment Share on other sites More sharing options...
22daz Posted June 1, 2023 Share Posted June 1, 2023 Just to add, I have the Mazda box and have never noticed any chatter. However changing to Redline had made it far nicer to use and much less notchy. I concur that it has definitely got better with miles as I thought there was something wrong with it initially. Now after 2 oil changes plus the original oil and still well under 5k, it is becoming delightful to flick through the gears.22daz Link to comment Share on other sites More sharing options...
StevehS3 Posted June 1, 2023 Share Posted June 1, 2023 #21 The chatter on overrun in 4th seems to be reported more on the Sigma and lightened flywheel combo. What engine is yours?Agree the Redline gearbox oil makes the Mazda box a delight. Link to comment Share on other sites More sharing options...
ScottR400D Posted June 1, 2023 Share Posted June 1, 2023 The Duratecs have a chatter as well, at least mine and most everyone I know with a Duratec has the same and regardless of gearbox. i believe, and was told this by SPC, that it's the CWP as a result of firing pulses and light flywheels. RRT thought it was the CWP and caused because of the engine being canted forward a couple of degrees. That idea has merit but I think the first idea is more likely. Mine is most noticeable in higher gears at low revs. Not to say there's isn't something else in the Mazda box that chatters but the diff chatter on light throttle/light overrun is common on all engine/box variants. Link to comment Share on other sites More sharing options...
Graham Hutton Posted June 1, 2023 Share Posted June 1, 2023 I absolutely agree and the noise in mine has always been worst in 4th gear on overrun. I put the redline MTL oil in over the winter and i'd say it is about 20% quieter as a result. ie, still bloody noisy :-) Link to comment Share on other sites More sharing options...
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