Gearbox noise - Sounds kinda nasty

[kgb]

Hi guys,

Had a search around and couldn't find something that sounded exactly like my situation so I thought I'd ask the question.

I get my MPS serviced by a local mechanic, not mazda. As such, I don't think my gearbox oil would have been touched.

I've been getting noise from the gearbox or diff for some time now, but it's getting worse. It doesn't do it when it's cold. Only when warmed up, if it's taken a bit of a punishment for a little while it will be even louder.

It happens at almost all speeds, but not under any form of acceleration, just when coasting... Also, while coasting, if i push the clutch in the noise goes away.

I have a reasonable understanding of what diff wine sounds like, and this isn't a high pitch noise at all. More of a continual crunchy grind sound, posibly a metalic sound.



Any ideas?


-Edit: I'm at 73,000km / first owner / mps gen 2

[KFuNk]

Try this!!! Gen II @ 73km good to see ya driving her well!!

The definitive gearbox oil thread

[rayd]

sounds like a clutch throw out bearing ... like this? YouTube - ‪Throw Out Bearing or Input Shaft Bearing?‬‏

[andy b]

Why don't you go to Mazda to have it looked at? As long as the log book has been followed by a licenced mechanic you are still covered by warranty.

Unless of course you are supposed to have had a gearbox oil service by now (I have a 6 so not sure of 3 specs)

[turkminator]

This happens to me in my gen 1 as well from what i know it's normal it's got to do with the type of clutch.. It's come up on the forums before as long as the noise is gone when clutch is in..

[MPS2NV]

If its noisey also while stopped I would suspect internal bearings of gearbox, if its only while car is moving it may be a drive line component also.

[kgb]

yeah, i'm working on getting it to mazda... hard to find time. I work 6 days a week. My mechanic is VACC acredited so I don't have any worries with warranty, although he does the usual country cars and I don't think a commodore or falcon would get a gearbox oil change in a lifetime lol. So was just kinda thinking that if it was needed under the 70k area, that he may have overlooked it.

I did have a look at the gearbox oil thread, I've never owned a manual car from new long enough to need a gearbox oil change. I'm not sure I'd discribe the noise as a woong woong. There's definately no gaps in the noise, it's constant when it's there, but it is a rotational sounding noise i guess.

Doesn't happen when not in gear regardless of clutch location. Only happens when in gear and coasting, it becomes very very apparent when in low speed car parks in first and i roll along in gear but with no foot on gas.

I thought it might be thrust bearing, but that would do it all the time i'm fairly sure. Even when stationary.

[kh92]

"It happens at almost all speeds, but not under any form of acceleration, just when coasting... Also, while coasting, if i push the clutch in the noise goes away."

This is one of my few current problems with my car, except the better described noise for it on mine is similar to brakes rubbing against the rotors, I know it's not the brakes because when I push the clutch in or the car rolls on neutral, it doesn't happen.

[boost]

I have a very similar noise.... Sounds similar to what kh92 described.

Like a very light metal on metal sort of sound (similar to brakes rubbing against rotors but quieter). Goes away when I push the clutch in.

Mazda told me it's the thrust bearing but I am not convinced.

[Victa]

Thrust bearing will go away with the clutch all the way out, or all the way in (sometimes)...

Apparently flywheel can also make noises like this... when I was speaking to Mazda they told me thay had recently had a car in they were convinced was throwout bearing, until they pulled it apart and found a rooted flywheel...

<mutter> Stoopid Dual Mass Flywheels </mutter>

Chris.