New guy, probably old question

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gladeparkfly

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Hey guys, newb here, currently moparless but I've got a few in my past. '73 charger SE, '72 swinger, '69 satellite, all automatics.
I'm trying to help a neighbor that's not real mechanically inclined diagnose an under dash noise that popped up when he had his clutch replaced. Car is a '70 duster, 340 4 speed and it's developed a strange metal on metal clatter high under the dash. Definitely not an underhood sound and having looked at the exploded view diagrams of his clutch linkage, I can't see anything obvious. It occurs near the top of pedal travel as he lets the clutch out, say the last inch or so before it hits the stop... Any ideas would be GREATLY appreciated.
Oh and just so ya don't think I've gone completely over to the dark side, My chevy powered all steel model 1920 T RPU is running a '33 Plymouth axle with '59 D100 drums. :) Again, thanks in advance for any hints, tips or ideas to get us pointed in the right direction.
 
Sounds like the clutch is adjusted wrong to me.

Old cars like about an 1 inch of free play before the clutch ingauges in the pedal.

So you can push down on the pedal around 1 inch before you feel any resistance
 
GEO said:
Sounds like the clutch is adjusted wrong to me.

Old cars like about an 1 inch of free play before the clutch ingauges in the pedal.

So you can push down on the pedal around 1 inch before you feel any resistance
Click to expand...


It has right at an inch of free pedal, Geo. Engagement is smooth and solid, feels good runnin through the gears. It almost sounds like a bracket moving around but I can't find a single thing that looks or feels loose.
 
Does this noise stop after the clutch pedal is fully out or does it continue while being driven?
Does the noise happen if the transmission is in neutral and the clutch let out?
Does the noise happen while the clutch pedal is being stepped on, or only while being let out?
You are sure it's coming from under the dash?
Almost sounds like a U joint going bad.
C
 
It's definitely coming from under the dash, happens under acceleration at low RPMs but not in neutral sitting still at least not that we could duplicate anyway.. Is the spring you mentioned listed in the exploded diagram of the pedal linkage as an "over center spring"? It does appear to be slightly touching part of the linkage next to it and I can see how that may telegraph this noise up under the dash. The best description I can come up with is a rapid metal on metal clanging noise, seemingly independent of engine RPMs or road speed... Honestly, I figured I'd look under the dash and spot something loose without much trouble, it sounds like it should be obvious if you know what I mean.

ETA it does stop once the pedal is all the way out, but oddly enough, it varies as to when it quiets down. Sometimes it quiets as it's still coming up and sometimes it doesn't quiet down until right as it hits the stop.
 
There is supposed to be a cage around that spring on V8 cars.
I suppose the header could be vibrating on the Z-bar, and thats coming up the pedal rod at that particular point in its travel.
 
What kind of pressure plate does it have? If it does not have the original type Borg and Beck three finger type and has been changed to the diaphragm type, that could be the problem. The over center spring should be removed with the diaphragm type pressure plate.
 
When you say "clang", I hear "rings like a bell". There is only one part among all that system that can clang.And thats the flywheel. And only if its loose on the crankshaft. And I have no idea how that sound could get up under the dash.
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It seems to me the most likely candidate for the creation of the sound should be the release bearing.Again the sound would have to travel up the rest of the parts.There is supposed to be a spring from the release fork to the bellhouse, to withdraw and park the fork when disengaged.But I just dont see any of these being the culprit.
I do see the engine straining on its mounts, and the header slapping the Z-bar. This doesnt happen in neutral,free-reving. My TTIs pass pretty close. If the Z-bar is not restrained, on its bushings,at one end, by that special wire retainer, it (the bar)can move over and climb into things.
 
Was any of the zee-bar removed for any reason? There are two nylon half-moon bushings on each end. If one was missing the vibes from the drive train might be transmitted through the clutch pedal assembly to under the dash. Just a thought.
 
Rusty what type of spring system do you use on a Diaphragm type Pressure Plate
 
Thanks for all the input guys. Not sure what type clutch he used when it was replaced but I'll ask him, Rusty. He had some guy across town do the work so I'm betting its the cheapest autozone replacement part he could find. The other ideas give me a few things to check out too. Stay tuned and I'll be sure to let ya'll know WHEN we figure it out. Not if, when. :)
 
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