Rep Power: 0

I have an 01 civic lx and after hours of scanning the internet I'm getting answers, but they contradict each other haha. I have an odd noise when my foot is off my clutch- a weird rattling. When I put it in gear and accelerate through them (mostly just gears 1-3) I'll get a weird whirring noise after about 2k rpms. I've had people tell me its both my input shaft bearing and throwout bearing. I myself thought it was the throw out, but I've been hearing both and if I rip my tranny out and replace one and have it be the other, I'm gonna be bummed. Any help would be so awesome!

 
Rep Power: 193

Since pushing in the clutch makes the noise go away its the ISB. When the clutch is in everything in the transmission stops spinning, that's why the noise goes away.

A bad throw-out bearing would be the opposite, making noise when the clutch is in, stopping when it's out. The only time the throw-out bearing spins is when you're on the clutch.

My '05 is making the same whirring noise in gears 1-3, just now developed it at idle, still hard to hear though so I'm not that worried about it yet. I plan on pulling the tranny myself and taking it to a tranny shop to have them do the two mainshaft bearings and the two countershaft bearings. Our trannies are actually very well built and will go 200k+ miles before needing a full rebuild. Just that pesky ISB has been a weak link for years. If the tranny still shifts fine then I'd just swap out the bearings.

Sure do wish Honda woulda built our trannies a little better, just be glad you have a manual and not an auto which have many many problems.

 
Rep Power: 367

need take tranny out? good time to have it checked and service all that needs to be done. not much to think about, except for the price tag. taking tranny out not so long afterwards is just... more expensive anyways...