Clutch Noise - Logic Check
05-29-2009, 01:48 PM
#1
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Clutch Noise - Logic Check
There is a strange whirring noise coming from my car with the clutch out. Push the clutch in, noise is gone. Same in every gear, neutral as well. This is the pilot bearing, right? If so, is this something that needs to be repaired very soon or can I drive on it for awhile? When i'm driving it sounds like i've got a supercharger. Its similar to the noise that Jeremy Clarkson's Alfa was making in that episode of Top Gear with the Alfa challenge (if anyone remembers that).
All my clutch parts came from the mazda value clutch kit from rosenthal and have >4k on them.
All my clutch parts came from the mazda value clutch kit from rosenthal and have >4k on them.
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05-29-2009, 02:07 PM
#2
Boost Czar
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you ready for this:
Miata Magazine, Spring 1991, Tip Sheet, page 14
Throw Out Bearing Noise
Many owners have mentioned a slight rattling noise at idle with the transmission in neutral and the clutch out. This comes from the throw out bearing. Most folks find that it gets worse when their air conditioning compressor is engaged due to increased idle rpms and engine vibration. In the old days, throw-out bearings were pulled away from the plate when the clutch was released. They then stopped spinning. In Mazdas these bearings are kept in constant engagement with the spinning clutch pressure plate. This design has a much longer life. However, any sloppiness in the internal bearing results in some noise.
If you have a 'chirp' instead of a rattle, some relief may come from greasing the tip of your clutch slave cylinder push rod where it meets the throw out arm. This quells the cricket-like squeaking caused be the metal to metal contact of these parts.
The rattling noises come from the throw out bearing itself. There is no cure other than replacement, and the new part will probably make the same noise. For now this goes under the category of "character."
Throw Out Bearing Noise
Many owners have mentioned a slight rattling noise at idle with the transmission in neutral and the clutch out. This comes from the throw out bearing. Most folks find that it gets worse when their air conditioning compressor is engaged due to increased idle rpms and engine vibration. In the old days, throw-out bearings were pulled away from the plate when the clutch was released. They then stopped spinning. In Mazdas these bearings are kept in constant engagement with the spinning clutch pressure plate. This design has a much longer life. However, any sloppiness in the internal bearing results in some noise.
If you have a 'chirp' instead of a rattle, some relief may come from greasing the tip of your clutch slave cylinder push rod where it meets the throw out arm. This quells the cricket-like squeaking caused be the metal to metal contact of these parts.
The rattling noises come from the throw out bearing itself. There is no cure other than replacement, and the new part will probably make the same noise. For now this goes under the category of "character."
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05-29-2009, 02:34 PM
#4
If you press the clutch in and the noise is gone, it's not the pilot bearing or throw-out bearing. The only time the pilot bearing and throw-out bearing are spinning (put to work) is when the clutch is depressed.
It might be a transmission input shaft bearing issue.
Can you make a recording of the noise?
It might be a transmission input shaft bearing issue.
Can you make a recording of the noise?
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05-29-2009, 04:43 PM
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If you press the clutch in and the noise is gone, it's not the pilot bearing or throw-out bearing. The only time the pilot bearing and throw-out bearing are spinning (put to work) is when the clutch is depressed.
It might be a transmission input shaft bearing issue.
Can you make a recording of the noise?
It might be a transmission input shaft bearing issue.
Can you make a recording of the noise?
What are 6sp's running these days?
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05-29-2009, 09:30 PM
#9
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So a squealing noise with the clutch out is fine? Mine squeals and when I push the clutch in it goes away. The squealing sounds kind of like a drive belt slipping. I feared it was the throwout bearing. This definitely eases my mind.
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05-29-2009, 10:21 PM
#10
I want to comment on the Tip Sheet that Brain posted.
The information that the throwout bearing causes the rattle noise is incorrect. The reason that Miatas have the rattle noise with the A/C on, comes from an internal transmission design issue. The counter gears in Miata transmissions don't have a friction gear that is designed into most modern transmissions. The friction gear's job is to take up any slack in the clearance between the mating gears of the individual gear clusters and the counter shaft. Without this friction gear, a rattle at idle with the a/c is what results.
Proof of this is easy...overfill you transmission past the normal mark and the noises will stop. Why? Because the overfilled oil drowns out the counter shaft.
Now, I don't know if this is related to the issue of OP, but hopefully he can get a recording of the noise and this can be ironed out.
The information that the throwout bearing causes the rattle noise is incorrect. The reason that Miatas have the rattle noise with the A/C on, comes from an internal transmission design issue. The counter gears in Miata transmissions don't have a friction gear that is designed into most modern transmissions. The friction gear's job is to take up any slack in the clearance between the mating gears of the individual gear clusters and the counter shaft. Without this friction gear, a rattle at idle with the a/c is what results.
Proof of this is easy...overfill you transmission past the normal mark and the noises will stop. Why? Because the overfilled oil drowns out the counter shaft.
Now, I don't know if this is related to the issue of OP, but hopefully he can get a recording of the noise and this can be ironed out.
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11-26-2009, 11:16 PM
#11
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Ok so if it's not the pilot or throw-out bearing in this case then what is it? Cause I reacently ran into this problem with a rattle only a week after replacing the clutch, throw-out, and rear main seal.
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11-27-2009, 04:22 PM
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When picking up my finished manifold from Sbkcocker 2 nights ago, something went clunk in my drivetrain and now its making the most horrid noise i've ever heard. It only makes the sound on decel, but sounds sort of like a baseball card in bicycle spokes, but amplified times 1 million in volume. The car drives just fine and I dont hear the sound when i'm holding steady speed or accelerating. It makes the sound but much quieter when in neutral or when the clutch is pushed in. It definitely follows wheel speed, not engine speed.
Tranny is coming off this weekend. I really hope that I didn't toast the tranny cause I am dead broke right now :(
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11-27-2009, 04:34 PM
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I misdiagnosed this noise on my car and it was actually from the transmission. My worn out 5 speed will just have to stay noisy. I was sure it was the throw out bearing since I have had throwout bearing issues on just about every car I have owned, but its for sure the transmission. I would guess the input shaft. The noise matches the rocks in a can noise from the worn gears at idle.
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11-27-2009, 04:36 PM
#16
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Coincidence indeed, that's what threw me off, I hate posting in a necro thread. No idea what the problem is, but if its not painfully obvious that either your pilot or throw out bearing has completely exploded, I'd say the tranny is fucked and you'll need another. It's not the best solution, but thankfully 1.6 5spds are fairly cheap.
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11-27-2009, 04:42 PM
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Someone locally has one for sale for 80 bucks. I'll have to try and get in contact with him.
I may try and borrow money from someone for a 6-speed but not sure yet. I'd like to not have this problem again...
I may try and borrow money from someone for a 6-speed but not sure yet. I'd like to not have this problem again...
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11-28-2009, 08:41 PM
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Its officially toast! About 10 mins ago I was driving home from a friend's house up the street and was accelerating in 2nd and it made some pretty crazy sounds and wouldn't move under its own power anymore. 4th gear worked barely to get me going enough to get to my alley and then pushed it from there.
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