whirring gearbox?

[vinnY]

ever since i've gone back to my stock exhaust i've noticed that whenever i'm downshifting there seems to be a somewhat loud whirring sound coming from the front driver side

driving seems smooth and braking seems fairly normal, just an odd sound coming from the gearbox
recently changed gearbox oil and didn't find any metal shavings

anyone had a similar problem? i'm not sure whether i explained the situation properly but if you have any questions i can try to elaborate on the problem if i can

[Spunkymonkey]

do you notice the sound stops when you put the clutch in? might be input shaft bearing in the gearbox

[bennjamin]

normal issues seem to be the input shaft bearing ( located inside the gearbox) or the release bearing ( located OUTSIDE the gearbox , on the clutch engaged fork).
Both parts need the gearbox to be removed to replace.

Put your EAR to your gearknob , while the car is idleing. Can you hear a slight whine thru the gearknob ?

[vinnY]

thats the strange thing, theres no noise on idle or in motion, no different from having the clutch engaged or disengaged
it only happens when i downshift(lots of engine vibrations with the synchros spinning up?) while when i rev match it seems to be smooth sailing

also notice it slightly if i just let go of the throttle, as the car jerks back a bit from compression braking, it makes the same noise intermittently so it might be something along the drive shaft i need to check out

i mean for all i know its just a loose heatshield bolt or something but at the moment i'm looking at the gearbox since it only happens when i'm downshifting or coasting in gear