Okay guys, I have a problem I though maybe you could help me with. I am trying to track down a noise I started hearing today. I noticed it when I was in gear and driving at speed (55 mph). It sounds kind of like a faint metallic grinding sound, coming from somewhere in the center of the car.

After much trial and error, I realized it was the transmission. In neutral I can hear the sound, while it seems to be slightly louder once I am in gear going over 45 mph or so. The odd thing is that once I push the clutch in, the noise disappears. With the engine running and the clutch in, I can go through all the gears and no weird sound. But take it out and put it in neutral, and I can hear it. Mind you, its not gear whine, as it is a completely new sound I noticed today.

Background is that I changed to the AFE SS about 2 weeks ago, which increased the gear whine (as expected) but not other strange sounds. Last weekend (4/7), I changed the transmission and differential oil to RP MaxGear 75W90 (1.9 qts. in the front and 1.4 quarts in the back), using new crush washers for both the drain and fill plugs. The only bad thing I did was not have my correct torque wrench and just tightened the plugs until they were plenty tight. I noticed an increase in notchiness in the shifting while cold, but a similar feel to stock when warm. I noticed no additional weird sounds.

The last "thing" that I did was take out and check the air filter box. When I did, I noticed I was missing one of the bottom grommets for the box, although I suspect the dealership lost it when clearing the oil out of my box for the ventilation TSB.

With all that background on what it could be, any ideas? My first is that somehow I am low on transmission fluid or something, causing the sound.

Thanks in advance.

Normally, I'd just blast you for avoiding the search feature.

However, I feel it might be more effective to simply list all of the painfully obvious threads discussing this well known, well documented "feature" of our transmissions.
The overwhelming volume of information available about this should be embarrassing enough.
Perhaps next time you could be bothered to try this out for yourself.

http://www.rx8club.com/showthread.php?t=51489&highlight=tranny+noise
http://www.rx8club.com/showthread.php?t=112267&highlight=tranny+noise
http://www.rx8club.com/showthread.php?t=13598&highlight=tranny+noise
http://www.rx8club.com/showthread.php?t=105669&highlight=noise
http://www.rx8club.com/showthread.php?t=28122&highlight=noise

Well, see I've been on the forum awhile, reading every post posted and know very well all of the noise our transmission makes. This sound, however, is brand new and came out of nowhere. It wasn't a gradual, "oh what is that", it was a "what the hell is that". That's why I posted, asking if this was a different sound, since it appeared out of nowhere.

Also, most of the links (which I have read) have to do with the gear in neutral. My noise gets louder the faster I am driving (not RPM related), which seems to be different than most. From the day I bought, until now (10673 miles) it has sounded one way, and today it became very much different.

It's not a whirring.
It's not a whining.
It doesn't sound like the gears.
It's a grinding sort of sound.

I'll get to reading the links you found for me, hopefully I'll find something new the second time I read them.

You already explained what is different - the AFE and the gear oil.

My stock clutch blew when I hit 20k miles...I only did daily driving, commuting between work and picking up my kids...Mazda refused to cover it under warranty because of my K&N Typhoon intake...WTF?

My stock clutch blew when I hit 20k miles...I only did daily driving, commuting between work and picking up my kids...Mazda refused to cover it under warranty because of my K&N Typhoon intake...WTF?

u r dumb.

http://www.rx8club.com/showthread.php?t=104756

good luck.

beers :beer:

u r dumb.

http://www.rx8club.com/showthread.php?t=104756

good luck.

beers :beer:

+1, anyways 20k miles? wow... im at 30k and the stock clutch is still going strong for me, i think i got the lucky 8 :)

You already explained what is different - the AFE and the gear oil.

I changed to the AFE SS and I had increased gear sound, but not this new sound. Not in 2 weeks. I changed the gear oil, no change in sound for 1 week.

I am attuned to the sounds of my car. I would have noticed this sound when I changed these things, but I didn't. I came later, all of a sudden, which was the cause for alarm.

This is the last time I'll ask about this. Just going to see what the dealer will say.

Well, I took out the AFE SS and put the stock shifter back in during my lunch break and that has seemed to help a lot, but not completely. I think that I may be a little low on transmission fluid, so I'll try to add some first chance I get. Anybody know what stores carry Royal Purple gear oil? Also, anyone know why a sound would appear out of the blue like that? Thank you for everyone's help.

PS. Going back from the AFE SS back to stock makes it feel like I am driving my old 94 saturn. What a difference in feel.

+1, anyways 20k miles? wow... im at 30k and the stock clutch is still going strong for me, i think i got the lucky 8 :)

When I change my clutch out I had about 27.5K miles, my clutch was nicely smooth, meaning its already slipping.

I guess it depends on driving , for areas with tons of stop and go traffic (hint hint new york). It dies alot faster.

I just hope that the new clutch (ACT hd with street strip disc) wont die for 20K miles :(