Big1000

Hey there HT

I'm trying to chase down a strange sound that I think is coming from my tranny. I fear that its a bad bearing somewhere-

A little background-
I got this 1997 civic HX MT, 130k miles, that had a bad input shaft bearing. I replaced the isb, new fluid, bearings, new clutch- the whole 9 short of a tranny rebuild. I replaced the isb because there was a pretty heinous noise when decelerating in gear, and under hard accel. Totally fixed that sound.

Now, theres a very slight sound when I'm idling in neutral. when I press clutch in it goes away. Sounds like it could be bad isb right? well it doesn't make the noise under hard deceleration like it used to- like way better, and its got a brand new Honda isb.

so I was replacing the tie rods last night and I spun the wheels with the car off the ground and the gears sounded pretty damn loud. like there wasn't any grinding or anything like that but I was like damn, those gears sound LOUD. obviously the car was in neutral, so I think it would have just been the diff spinning.

Anyone know what this might be? could a bad diff or some bearing in the diff be causing this? or is it normal for the diff gears to be fairly loud when spinning wheels off ground?

thanks

Big1000

Big1000

Txdragon

Noise that disappears when you push the clutch in while the car is running usually indicates throw out bearing. I had a similar issue twice, full clutch and TOB replacement, noise went away. Noise returned a month later, replaced TOB (evidently got a dud with the clutch kit), noise gone again and hasn't returned after near 7 months.
Spinning your wheels while car is off the ground, you're very likely to be hearing brake noise; pads rubbing a bit on the rotors as the wheel spins freely. This, I believe, would have nothing to do with the sound you hear while driving.

Big1000

LiteraCola

Are you sure theres no chicken in there?

mk378

You can isolate the throwout bearing by moving the clutch lever slightly toward the slave cylinder (pushing the cylinder piston in). This will move the bearing away from touching the springs on the clutch cover and it will stop rotating. Move the lever only slightly, if you push hard on it, it can get detached from the pivot ball and that is a real pain.

Noise idling in neutral that goes away when the clutch is pressed is also often from the input shaft bearings in the transmission. This is best checked by rotating the shaft by hand with the transmission out of the car.

Big1000

not exactly sure what you mean here- are you meaning to stand in front of the car and move the the lever towards the slave cylinder, like opposite from the normal operating direction of the slave cylinder? that kind of makes sense that it would make the throwout stop spinning.

yeah. I really hope that isn't it because I just replaced it

forbiddenera

I dunno, my car spins in neutral w/clutch out and makes a little noise similar to what you describe and I don't have anything wrong.