New clutch...Noise when clutch is not depressed and trans in N?

[Civilizedape]

After I installed a new clutch on my L28 w 5 speed I have some noise that I can only assume is the throwout bearing. Could be wrong though. When the clutch is pushed in theres no noise but when the clutch is out and trans in N there is a noise from the clutch area. Any thoughts? I know about the throwout bearing collars being diff sizes but I think I have the correct one. Could I have misaligned the clutch installing it?

[Zed Head]

One of the bearings in the transmission is known for making noise.  I think it's the countershaft bearing.  Doesn't hurt anything it's just annoying.  There are stories of replacing the bearing with a new one and have ing the nosie come back within a very short time.  Might be why Nissan went to a bigger bearing with the 71C transmission.

What kind of "some noise" is it?

[siteunseen]

My '77 does the same, whinning spinning noise until I push the clutch pedal down.

Zed Head knows way more than me on these cars especially transmissions.

I can say this from my personal experience. I drove the throwout bearing on using the old one as I had read online. I had the throwout bearing pressed on the collar at a machine shop on my 240. No noise, same clutch kit. Just putting that out as more info.

[EuroDat]

I take it that L28 is in a 280Z. Did you do anything to the slave cylinder? Change it for another unit?

Reason for asking. The 280Z slave cylinder has a spring behind the piston. It has two functions: 1. Prevent free play in the mechanicals between slave clinder and throwout bearing. 2. Keep the throwout bearing on the pressure plate so it spins with the pressure plate and doesn't slip. If it slips, it generally squeals or makes a peeping noise that comes and goes.

It is easy to test. The noise will disappear if you apply the clutch a little.

 

[Civilizedape]

I would say it sounds like a bearing noise. It's not very loud it could in my mind be the throwout bearing and pressure plate not contacting properly.

The slave is a older non internal spring adjustable. It has a tab for a spring. I installed a spring but it does not quite the noise. Nor does holding the clutch fork back fully remedy the noise.

The noise goes away with clutch depressed. 

[cgsheen1]

+1 for transmission bearing noise.

[ETI4K]

It's quite odd that, presumably, the sound was not present before the new bits went in.

There's no chance it's clutch misalignment.  The disc is the only component that could be misaligned, and if it were, you'd never get the trans back in.  And even if you were to get the trans reinstalled with a misaligned disc, as soon as you depressed the clutch pedal, the disc would be freed to center itself.

Noises are the hardest to describe.  If the release bearing were in light contact with the pressure plate, it would be making some sound - audible or otherwise. Depressing the clutch would load the bearing past its light load, incidental contact condition and either make it sing or reduce its sound level. 

Try readjusting the throw on the master cylinder to ensure ample clearance (free-play) in the pedal. 

It is possible that the parts you received are not correct (can you say misboxed?).  It's happened to me.

Are you certain the clutch release lever is properly seated on the pivot post, and the lever has freedom to move?

Be certain there's no residual pressure on the clutch slave.  Cracking the bleeder will let you know - if brake fluid blows out, not passively drips out, then you had some force acting on the release lever.

Well that's  it.  I'm in the middle of cocktail hour!??

 

 

 

[siteunseen]

I'm towards the end! This quarantine upped my start time.

 

[ETI4K]

site: I think we're all with you!

 

[siteunseen]

Cheers!

[Zed Head]

This has the classic signs of noticing something that has always been there because you just did some work in that area.  I had three different five speeds in my car that all made the bearing noise.  Different sleeves, pressure plates, etc. but they all sounded about the same.  Pedal down, noise gone; pedal up, noise there.

Drive it for a few days and see if it changes.  It will probably get a little louder when the oil is hotter and thinner.

[David F]

My 72 with 79 280Z five speed makes the same noise.  Clutch out, noise.  Depress clutch, noise gone.  All new clutch components.  As others have said, my assumption is that it is not the throwout bearing as there is no load on the bearing when the clutch is out and the noise is present.  If I depress the clutch slightly, the noise stops.  So, I guess it could be throwout bearing slop/end play at work.

But, the noise certainly sounds like bearing noise which I assume was the input shaft.  I'm living with it....