Throw out bearing noise.

[cvette98pacecar]

Seeing as most of you are experts. Is is normal for the ZF6 throwout bearing to be noisy when the clutch is disengaged and you are not in any gear?

[mike100]

My blue label ZF6 did this loudly in my 95 LT1 car, but my current 91 LT5 car is pretty quiet and maybe more so since the Bill Budreau got his mitts on it. Seems to me that the t/o bearing isn't loaded with the clutch pedal out as most cars I had would make noise when you depressed the clutch.

Then again it's a pull type pressure plate deal. It is also possibly normal gear whine from the trans which is completely harmless if the lube oil in it is full.

[tccrab]

Yup.
Mostly it's from the ZF6 tho and not the throwout bearing.
Even with the DM flywheel it's noticeable.
Put in a single mass aluminum flywheel on a stock transmission and you will hear something described often as "A Box Of Rocks Tumbling Around".
Bill Budreau, the ZF Doc has a cure, but it involves rebuilding the ZF6.

TomC
'Crabs

[Hammer]

Seeing as most of you are experts. Is is normal for the ZF6 throwout bearing to be noisy when the clutch is disengaged and you are not in any gear?

Not that I'm aware of, unless you have an aluminum flywheel. But then, you aren't hearing the TO bearing.

[cvette98pacecar]

I got an extra in Chicago out of a totaled LT-1 maybe I will just send that to Bill to rebuild.

[rhipsher]

NEW GUY!:mrgreen:

[richard sanderson]

In my humble experience, the throw out bearing noise only occurs if the bearing itself starts revolving in its housing. The noise makes you think a tomcat has got in there, and has got it's chebs caught in the crankshaft. Any other transmission noise heard when the clutch is depressed will probably be just a bit of general wear and tear. Maybe bleeding the clutch might quieten things down?

[Kevin]

Yup.
Mostly it's from the ZF6 tho and not the throwout bearing.
Even with the DM flywheel it's noticeable.
Put in a single mass aluminum flywheel on a stock transmission and you will hear something described often as "A Box Of Rocks Tumbling Around".
Bill Budreau, the ZF Doc has a cure, but it involves rebuilding the ZF6.

TomC
'Crabs

it also leads other motorists to ask you if you have a rod coming out of the block

[Paul Workman]

I got an extra in Chicago out of a totaled LT-1 maybe I will just send that to Bill to rebuild.

Well, the input shaft and noze on the ZR-1/LT5 ZFs are different: the shaft longer and the nose larger diameter. Bill may have those parts available to convert your ZF, but ya might wanna axe 'im! :)

I'm just sayin...

P.