Bearing noise when clutch is engaged

[kimokalihi]

I've been driving my GF's 2000 honda civic LX 5spd and I've noticed it has the same noise but not as loud as one of my 5spd legacy 90 L wagons had. When you push the clutch in it goes away completely but when you let the clutch out you hear the bearing making noise. It's almost like a grinding noise. Hard to explain, basically just sounds like a worn bearing.

Which bearing is it or is it even a bearing? It's not the throwout bearing right? Wouldn't that only make noise when the clutch is in? If I understand correctly the throwout bearing is only used when you push the clutch in, right?

Could it be the bearing that sits in the flywheel on the input shaft? If so, maybe I should replace the clutch on that tranny in the subaru.

I've got a brand new exedy clutch kit for that civic waiting to go in. I need to find a flywheel or get hers resurfaced though. I'm always weary about resurfacing things though and usually just replace them.

[vrg3]

I think I may have had the same problem before. It sounded like the rattling of a worn bearing and pressing the clutch pedal even just a little bit made it stop.

It went away after I did a clutch job. I replaced the flywheel, pressure plate, clutch disc, throwout bearing, and pilot bearing. I don't know which of those it was, but I actually would be inclined to think it was the throwout bearing.

The throwout bearing is under more load when you're declutching, but it is always there, riding on the transmission's input shaft. Maybe when you declutch you put a little extra tension on the bearing and that is what quiets it down. I dunno.

[kimokalihi]

That's a good theory.

I was thinking it was the pilot bearing because I thought the throwout bearing was completely disengaged when the clutch was engaged.

Luckily I will be replacing all of these things as well soon. I wanted to do it the other night but didn't have a flywheel to put in.

I wish I had known that. I would have put a clutch in that old subaru and bearings and sold it for a lot more than $400. A lot of people called about it but didn't want to risk having to do transmission work or replace the transmission.

[vrg3]

It could also have been the pilot bearing in my case. The pilot bearing's ball bearings aren't doing much when the clutch is engaged, but are rolling when you declutch. For all I know it was some weird situation where they were loose in their races and so rattled but quieted down once they got moving. But, yeah, you replace the pilot bearing when you do a clutch job anyway.

And I suppose there's always the slight chance it's a bearing on the transmission's input shaft. I don't know that much about the internal construction of the transmission.

I guess one way to know whether it's in the transmission or not is to pay attention to how much time passes between declutching and the sound going away. If it's immediate, it's probably not in the transmission because the input shaft takes at least several seconds to stop turning.

[Airgne]

it could be the piolt bearing fell out of the flywheel. did it on my 01 scooby.

[kimokalihi]

It goes away immediately when you push the clutch in. Same in both cars, the subaru and the honda. The subaru is real loud. Sounds nasty. Sounds about the same as the honda but louder. The honda actually goes away once you get going a little faster. It's only in the begginning of 1st and 2nd gear I think that you notice it. And while it's idling when it's stopped. The subaru does it loud the whole time you drive it. In all the gears.

[SLODRIVE]

My money's on a bad release bearing...on both cars.

[Legacy Konig]

Throwout bearing.

You hear a roar?

[kimokalihi]

There's a roar in the subaru but it's not nearly as bad in the honda. I have a feeling the subaru has been doing it for a lot longer than the honda though.