OldSchoolFormula

So my dad's Z06 is making some very unhappy noises. He's said the transmission has been fairly rough engaging and making a rumbling type of sound between shifts. I just got done bleeding his clutch with him thinking maybe the clutch was hanging up.

Bled it and it's doing the same - perhaps even worse. Hard to say since I didn't drive it beforehand. It grumbles between shifts and at one point didn't want to go into 2nd gear, just ground. Eventually got it into gear with a little rev match and we just drove it straight back. It makes a grinding sound in the driveway when revved, both with the clutch in and with the clutch out in neutral. It does not sound good at all.

We had the clutch replaced with an LS7 unit a little while back along with the hydraulic throwout bearing and if I remember correctly, we had a pilot bushing installed.

Right now I'm a little baffled as to what is but am thinking failed hydraulic throwout bearing. Anyone else encounter this? Bit stuck right now with the other DD being out of commission.

Kevin Kuse

Ok we need to find out exactly when you do & don't have this Noise!

1) Engine Running /Trans in Neutral / Sitting Still 0mph / Foot off clutch pedal.
Noise? Yes/No

2) Engine Running /Trans in Neutral / Sitting Still 0mph / Foot on clutch pedal. Light pressure.
Noise? Yes/No
Did Noise Change? Yes/No


3) Engine Running /Trans in Neutral / Sitting Still 0mph / clutch pedal depressed to floor.
Noise? Yes/No
Did Noise Change? Yes/No


4) Engine Running /Trans in Gear / Sitting Still 0mph / clutch pedal depressed to floor.
Noise? Yes/No
Did Noise Change? Yes/No


5) Engine Running /Trans in Gear / Sitting Still 0mph / clutch pedal depressed to floor.
Is the car trying to move itself? Yes/No

MawneeC5

^ Fantastic trouble shooting questions!

Get back to us with those answers and we can help

OldSchoolFormula

1) No noise.
2) No noise. When revved you get a very slight vibration at 3k+ as the clutch is slipping slightly.
3) No noise.
4/5. No noise sitting at idle. When revved, as the revs go up no noise. As the revs come back down again absolutely terrible noise and it does the car is trying to move itself. It also feels a little stuck in gear when it does this. It is also not consistent. First time I ran through these tests it did. The second time it didn't the first few times but then went ahead and did it. Grinding and trying to move the car.

Kevin Kuse

Pilot Bearing! While you are in there, check the input shaft were the bearing rides!
Also recheck the clutch set. Bummer!

Carcass

And when you replace it,I would recommend going with a Kevlar/Composite pilot bushing.

http://www.ramclutches.com/ (halfway down the page)

Your propshaft is going to be pretty well chewed up (that's what's happening when it's making the expensive noises)

Smooth the end of the propshaft down with Wet-or-dry#600,then polish it with Mothers till it's got a mirror shine to it. Do not lubricate it if you go with a Kevlar bushing-this just makes crap stick to it ,which will wear the bushing.
My Vette's been running for 6k with a Kevlar pilot, and it works sweet!

Kevin Kuse -Excellent troubleshooting guide !

vaportech

My 2000 is making a grinding noise only when leaving a stop at about 3/4 clutch travel to about 1/4 clutch travel coming from the transaxle. Any Help?

AF Vette

Bringing back a long dead post but I have very similar symptoms. It was actually my brother who made this first post and pointed me in this direction.

1) No noise
2)Very slight noise
3)A lot of noise
4)Same noise as #3
5)Car does not try to move itself

I'm at a loss here. I really hope this doesn't get expensive

**edit** Also if I just start the car I get no noise until it is either revved or put into then taken out of gear.

Kevin Kuse

From your answers, I would be looking Clutch Release Bearing and/or Clutch area problem.

AF Vette

So whole new clutch assembly replace both bearings? Just get it all done at once?

Kevin Kuse

Verify you that you found the problem upon inspection! Then Yes!