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View Full Version : Clutch chatter, what's that slap sound



volksnut
05-30-2016, 08:37 AM
I've posted this over at the tri-five forums and still looking for some ideas. Car is a '57 with late one piece seal crate engine, new front mounts, new bell housing mounts, new CPP cross member. Car was an automatic originally but was swapped over when I bought it but looks to have new linkage parts, has original GM 3704922 cast bell housing (which I've centered just recently), Hayes flywheel, Mcleod diaphragm clutch, Mcleod 5 speed. It chattered with prior Saginaw trans (video's) and still does it with new 5 speed trans. I've included these 3 video's for you to see what I'm talking about. It will do it when you just release clutch, and I mean a light release before engagement...it will render it's ugly head sometimes on down shift to 2nd gear. The only thing I haven't changed is the fork and linkage it was in car when I bought it
https://vimeo.com/129837265

https://vimeo.com/129837264


https://vimeo.com/129837262

Del Ray
05-30-2016, 10:11 AM
I experienced a severe clutch chatter in my '55 when first built. The first clutch was a oe replacement from RAM. When I pulled the clutch out of the car I visibly saw that the pressure plate and flywheel had hot spots on 1/3 of the contact surface, indicating unequal pressure plate spring pressure. I contacted Summit and they agreed to refund the cost of the clutch and I bought a McLeod Pro Street #75225 diaphragm clutch to install. Through the years I've had no problem with McLeod equipment. My original 168 tooth flywheel was surfaced and balanced before the first clutch was installed. No chatter now, no excessive pedal effort and smooth engagement.

Troy
05-30-2016, 10:40 AM
Is there a pilot bushing in the end of the crankshaft, and if so is it the correct size?

volksnut
05-30-2016, 11:45 AM
I experienced a severe clutch chatter in my '55 when first built. The first clutch was a oe replacement from RAM. When I pulled the clutch out of the car I visibly saw that the pressure plate and flywheel had hot spots on 1/3 of the contact surface, indicating unequal pressure plate spring pressure. I contacted Summit and they agreed to refund the cost of the clutch and I bought a McLeod Pro Street #75225 diaphragm clutch to install. Through the years I've had no problem with McLeod equipment. My original 168 tooth flywheel was surfaced and balanced before the first clutch was installed. No chatter now, no excessive pedal effort and smooth engagement.

It did the same thing with the old cast flywheel, 3 finger PP and 12" clutch

volksnut
05-30-2016, 11:48 AM
Is there a pilot bushing in the end of the crankshaft, and if so is it the correct size?

Well the engine came with the needle bearing and it did it then with the clutch set up above, then I replaced it with the good non metallic bronze bearing when I installed the 11" Mcleod.

chevynut
05-30-2016, 12:32 PM
Did it make that noise without the clutch installed? Are you sure it's not in the tranny? Sure looks in the video that when you let out the clutch the engine loads down. I see the engine moving around as the clutch is engaged and disengaged. Is the tranny in gear or in neutral?

volksnut
05-30-2016, 02:26 PM
Did it make that noise without the clutch installed? Are you sure it's not in the tranny? Sure looks in the video that when you let out the clutch the engine loads down. I see the engine moving around as the clutch is engaged and disengaged. Is the tranny in gear or in neutral?

Didn't start it without clutch installed. It's not the tranny, I thought at first it was the Saginaw that was in it, but it does the same thing with the new 5 speed. The engine does load down because it's in 1st gear. The car is moving a bit when I'm releasing the clutch, so that's why it looks like the engine is moving around. Like I said if you let the clutch out enough it doesn't chatter, just when you barley let it out.

chevynut
05-30-2016, 04:05 PM
So if it makes the noise with two completely different flywheels, clutches and transmissions, are you sure it's not coming from the engine? Has is ever NOT done it? I don't see how it could be related to the clutch if you've replaced everything but the fork. Almost sounds like an engine bearing knock to me just based on the video.

Let's think about this....the transmission is NOT turning so that can't be it. Neither is the clutch disc. The flywheel and pressure plate are turning. As you let the throwout bearing out it starts to make the noise. The pressure plate is moving toward the disc and both are moving toward the flywheel. Is something on the pressure plate hitting the clutch disc as it turns? Is the pressure plate hitting the flywheel bolts? Did you install the disc in the correct orientation? Does it ever make this noise when the clutch is engaged, or only when you start to engage it?

volksnut
05-30-2016, 05:37 PM
So if it makes the noise with two completely different flywheels, clutches and transmissions, are you sure it's not coming from the engine? Has is ever NOT done it? I don't see how it could be related to the clutch if you've replaced everything but the fork. Almost sounds like an engine bearing knock to me just based on the video.

Let's think about this....the transmission is NOT turning so that can't be it. Neither is the clutch disc. The flywheel and pressure plate are turning. As you let the throwout bearing out it starts to make the noise. The pressure plate is moving toward the disc and both are moving toward the flywheel. Is something on the pressure plate hitting the clutch disc as it turns? Is the pressure plate hitting the flywheel bolts? Did you install the disc in the correct orientation? Does it ever make this noise when the clutch is engaged, or only when you start to engage it?

Yes I installed the disc the right way, and no nothing hitting the disc, remember it did it with the other set up also. No it doesn't make the noise when engaged, only when it just starts to engage....if you engage it heavily it's smooth, only when you barely engage it will it do it.

Rick_L
05-30-2016, 05:40 PM
Something is making metal to metal contact.

Could be the clutch fork contacting the pressure plate. Thing is, the usual place it would contact would be with your foot off the pedal, not on it.

Could be the clutch disc on the flywheel bolts. As Cnut suggested, is the clutch disc installed in the proper orientation? The "tall" side goes toward the pressure plate, not the flywheel.

Rick_L
05-30-2016, 07:03 PM
Read your posts on the other site. Things look far more complicated than I thought.

Is there any noise when you engage/disengage the clutch with the transmission in neutral?

Have you checked the thrust clearance in the engine?

volksnut
05-30-2016, 07:41 PM
Read your posts on the other site. Things look far more complicated than I thought.

Is there any noise when you engage/disengage the clutch with the transmission in neutral?

Have you checked the thrust clearance in the engine?

No noise when engaged/disengage in neutral. No I have not checked the thrust clearance. I know working with VW's you have to, how do you on a Chevy? The thing is, the clutch pedal is hardly getting pushed when it makes this noise. I had a response on the other site that possibly it's the wrong clutch fork.

Rick_L
05-30-2016, 08:03 PM
I'd say it's only the clutch fork if it's hitting something.

After watching your video of the driveline I don't think that's it.

volksnut
05-30-2016, 08:43 PM
I just found this interesting. If you watch the second video (#265) at approx. the 15 second mark when it starts chattering look at where the flywheel and pressure plate meet. Is that the flywheel moving?

chevynut
05-30-2016, 11:19 PM
I hate to say it but I think your clutch disc is installed wrong. If I were you I'd pull the tranny and the clutch and as bad as that's chattering you should find some damage. I don't see how it could be related to the fork, and the whole engine shakes when it chatters. I think the clutch disc is hitting the flywheel bolts. Nothing else makes sense to me because the tranny isn't turning.

volksnut
05-31-2016, 08:26 AM
I hate to say it but I think your clutch disc is installed wrong. If I were you I'd pull the tranny and the clutch and as bad as that's chattering you should find some damage. I don't see how it could be related to the fork, and the whole engine shakes when it chatters. I think the clutch disc is hitting the flywheel bolts. Nothing else makes sense to me because the tranny isn't turning.

Flat side towards the flywheel, but here is an interesting tidbit. When I removed the original cast flywheel I noticed all 6 flywheel bolt heads were ground down. So I assume they thought it could be the problem also. Remember it's done this with 2 different clutch systems, a 12" 3 finger truck clutch and this 11" Mcleod.

chevynut
05-31-2016, 09:14 AM
When I removed the original cast flywheel I noticed all 6 flywheel bolt heads were ground down. So I assume they thought it could be the problem also. Remember it's done this with 2 different clutch systems, a 12" 3 finger truck clutch and this 11" Mcleod.

IMO there's some kind of mis-match in the clutch or flywheel parts. I would disassemble it and look closely at how the parts fit together. I thought a 1-piece seal crank took a different flywheel but I'm not sure.

volksnut
05-31-2016, 10:06 AM
I thought a 1-piece seal crank took a different flywheel but I'm not sure.

Yes it does and I have it

Rick_L
05-31-2016, 05:30 PM
You can't have the wrong flywheel and actually bolt it to the engine.

volksnut
05-31-2016, 06:07 PM
http://www.trifivechevys.com/attachment.php?attachmentid=6069&stc=1http://www.trifivechevys.com/attachment.php?attachmentid=6070&stc=1http://www.trifivechevys.com/attachment.php?attachmentid=6071&stc=1Here's the set up