Grinding noise? Throw out bearing?
Thread Starter
Instructor
Joined: Sep 2006
Posts: 124
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From: Chesapeake VA
Grinding noise? Throw out bearing?
I have a 2000 C5 conv with an MN6 with 45K miles. The car has developed a grinding noise over the last couple of months that I hear most noticeable when taking off in first gear. It sounds like it is coming from the rear of the car, but I only notice it when taking off. I thought it might be an exhaust rattle, but all seems tight. The clutch engages fine with no slippage and transmission shifts fine. I put the car up on stands and when turning the rear wheels by hand, their is no abnormal noise or play in the rear end, CVs or wheel bearings that I can feel. All fluid levels are normal and clean in diff and trans. I run synthetic ATF in the trans and synthetic mobile 1 75W-90 in the rear end with friction modifier. I am beginning to suspect it may be the throw out bearing. What is the best way to troubleshoot this and prove or rule out the throw out bearing. Appreciate advice. thanks.
Tech Contributor
Joined: Jan 2007
Posts: 19,340
Likes: 1,120
From: Dyer, IN
I have a 2000 C5 conv with an MN6 with 45K miles. The car has developed a grinding noise over the last couple of months that I hear most noticeable when taking off in first gear. It sounds like it is coming from the rear of the car, but I only notice it when taking off. I thought it might be an exhaust rattle, but all seems tight. The clutch engages fine with no slippage and transmission shifts fine. I put the car up on stands and when turning the rear wheels by hand, their is no abnormal noise or play in the rear end, CVs or wheel bearings that I can feel. All fluid levels are normal and clean in diff and trans. I run synthetic ATF in the trans and synthetic mobile 1 75W-90 in the rear end with friction modifier. I am beginning to suspect it may be the throw out bearing. What is the best way to troubleshoot this and prove or rule out the throw out bearing. Appreciate advice. thanks.
Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
Don
When you take off, experiment with pressure on the clutch peddle. See if riding the clutch a little or letting the clutch out quickly changes the noise.
What does it sound like out of gear with the clutch out and clutch in??
Bill
When you take off, experiment with pressure on the clutch peddle. See if riding the clutch a little or letting the clutch out quickly changes the noise.
What does it sound like out of gear with the clutch out and clutch in??
Bill
Thread Starter
Instructor
Joined: Sep 2006
Posts: 124
Likes: 0
From: Chesapeake VA
Bill,
There is no unusual noise when engaging and disengaging the cluth with the trans in neutral. Also, when taking off slowly, I don't notice any noise, so it is definitely rpm affected.
There is no unusual noise when engaging and disengaging the cluth with the trans in neutral. Also, when taking off slowly, I don't notice any noise, so it is definitely rpm affected.
Le Mans Master
Joined: May 2004
Posts: 5,683
Likes: 1
From: Houston Texas
I think I have the same noise 
Is it worse when the car is cold? Does it go away after a few starts from 1st? Stock clutch or aftermarket? Maybe it's the rivets holding the clutch disk together are contacting the flywheel when you engage the clutch. 
That's what I think is my problem, but I don't want to believe it.
Is it worse when the car is cold? Does it go away after a few starts from 1st? Stock clutch or aftermarket? Maybe it's the rivets holding the clutch disk together are contacting the flywheel when you engage the clutch. That's what I think is my problem, but I don't want to believe it.
Instructor
Joined: Jun 2008
Posts: 220
Likes: 0
From: Somers Point New Jersey
I think I have the same noise Is it worse when the car is cold? Does it go away after a few starts from 1st? Stock clutch or aftermarket? Maybe it's the rivets holding the clutch disk together are contacting the flywheel when you engage the clutch. That's what I think is my problem, but I don't want to believe it.
Is it worse when the car is cold? Does it go away after a few starts from 1st? Stock clutch or aftermarket? Maybe it's the rivets holding the clutch disk together are contacting the flywheel when you engage the clutch. That's what I think is my problem, but I don't want to believe it.
7th Gear
Joined: Jun 2015
Posts: 7
Likes: 0
Similar noise
I have an almost "ringing" (high pitched metal rattling) noise coming from the rear while in (I think) any gear, accelerating at low RPMs. I don't notice the noise while using the clutch, only while in gear. Any suggestions what it may be?
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Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
If you jack one rear tire off the groundm trans in "N" and try to spin that jacked up wheel, explain what you feel. Should be around 50-60 ft/lbs to break it free and then it turns smooth. Jack the other side and repeat.
Post results.
BC
Post results.
BC
