Drivetrain noise question
 

I have a noise coming from my drivetrain that sounds like grinding. It is most noticable during decelleration and between 3-4k rpm. It sounds sort of like normal transmission noise, but my 97 makes absolutely no noise at all, while my 90 is somewhat annoying.

However, while the 97 is stock, the 90 is equipped with mazdacomp motormounts and a spec stage 3 clutch. I also lost one of the stock driveline bolts and replaced it with one that didnt fit as well, but was told it should not be a problem. Also there is a possibility that ive got a loose nut somewhere as well .. ah the perils of teardown and rebuilding by a noob.

I can hear some gear noise from my 91 with the 140k mile oil and the new mobile 1.

btw, I had this same gear stack in my vw:
http://www.schimmelperformance.com/m.../LDSCN0036.jpg
it was like driving a blender.

akaryrye, i had some noise similar to what you explained, when i stepped on the clutch it sounded like a bad guy in a cartoon laughing, *evil laugh* hhh-hh-hhh-hhhhh... well a week later it turned out it was my throw out bearing... anytime i turned on the car and idled with the clutch pressed in it would sound like crap, as soon as i put it in gear it goes away...

this may not be your problem but
it sure sounds like it...

no, i have new throwout bearing. Sound happens in gear and clutch engaged.

so does it sound like low pitched wine, or a blender? Its probably just gear wine. Even though were talking about helical cut gears, they can be heard at low speeds. I think i can only hear when its quiet around me, and in first gear, and maybe 2nd.

Just for the hell-of-it, grease the end of the slave cylinder where it meets the fork. You never know.

whn my valves arent ticking i can hear the same noise your talking about. some guys pointed me towards it being the input shaft bearing. oh well, not like 5 spd's are expensive, when it breaks ill get another.

Ya i think its probably just typical gear whine and its pronounced by not having a center console or any sound deadening

and i have a spare 5 speed in case of any emergency too :)

Decern whether it's a drivetrain or transmission source by getting to the point where the noise occurs and putting the car in neutral. Noise stays = not a trans issue. Noise goes away = trans. Although not necessarily because the noise might be created by the vibration from the load on the trans during decelleration.

For example, I had a grinding noise during braking. After spending too much time on thinking/looking/testing the brakes, I posted the problem here. It turned out to be a loose exhaust component grinding, caused by the load shift while braking.

i can't hear shit on mine. lightened flywheel makes a lot of noise on decelleration.

I was a bit concerned about it being my flywheel slightly out of balance

Just to follow up on this (i was going through old posts) I swapped the 1.6 rear onto my 97, and the 97 onto the 90. Noise went away. I dunno why but i liberally applied grease to all the splines in the axles and changed the fluids while i was at it. Guess what, noise went away, go figure.