Clutch squeal when running

[CaptainMajestic]

Hi everyone,

been scratching my head over this one. I recently rebuilt my engine (+ all new seals), and while I was at it I went ahead and replaced my pilot bushing, throwout bearing, clutch, etc. and everything ran fine for several weeks. Suddenly, now the clutch squeaks any time I press it in when the engine running, but not when the engine is off. I've read online this sound is common with a bad pilot bushing, but this one is brand new? 

Video:

https://photos.app.goo.gl/r7FSh6LizfamRN5D9

 

74 260z with L28 + Round Tops and 4 speed tranny.

Thanks!

[Mark Maras]

 That sounds like a bad throwout bearing to me. The symptom of a bad pilot bearing or bushing that I've experienced is crunchy shifting in all gears but little to no noise when I pushed on the clutch pedal.

[siteunseen]

The squeal goes away when you depress the clutch. Bad throw out bearing. Could be backwards or not pressed on correctly. My 280 whines because my dumb a s s pounded it on the collar myself. 240 is quiet. I paid my machinists $10 to press it on.

[AZDatsun]

I had squeal when pressing clutch it was throwout bearing replaced that and it went away although now that I think about it I replaced the pilot bushing at the same time.


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[CaptainMajestic]

Hi guys, I finally got around to pulling the transmission and it is for sure the throwout bearing. 

https://photos.app.goo.gl/A2JWfv9DEgBtSZQa7 For evidence of catastrophic failure. 

 

Anyone know which direction the bearing is supposed to be pressed in? I have a feeling it put in backwards.

 

Thanks!

-Michael  

[CaptainMajestic]

Update:

By using the power of deduction I have determined that the bearing was probably pressed on backwards and therefore, once again, I am a total dumbass. The basic reasoning being around the throwout bearing is designed to press against the clutch spring and the shape of each side of the throwout bearing have different behaviors. If the side where the center is more pronounced faces the clutch, then the clutch springs can dig in and cause the entire thing to evaporate. If the side where the outer edge is more pronounced faces the clutch then the previous case cannot occur. 

 

[Patcon]

Good you figured it out.

[siteunseen]

We learn the hard way. Bet that won't need deduced again. 

Glad you fixed it.  Cliff