Slight clutch chatter

Dick Deegan

Dick Deegan

Well-known member
Good Morning All;

I have a slight clutch chatter and am trying to eliminate sources. I noticed that there is a lot of clearance between the trunion nut on the adjusting shaft and the clutch pedal.

Do you think that may be one of the sources of the chatter? If so, short of getting another clutch pedal, can I braze the hole and redrill it to the correct dimension.

Or does it not matter?

Dick
 
Clutch chatter is generally only from the clutch disc mating to the spinning flywheel surface. On almost every one of the Model A's that come in complaining about clutch chatter, I found an excessively worn pilot bearing and/or a worn transmission input shaft. Some say that a warped pressure plate will cause this too but that has not really been my experiences. The worn input shaft/bearing allows the clutch disc to engage 'out of centerline' which creates the jumping or grabbing that we generally associate as "clutch chatter".

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Shortly after installing float-A-motor rear motor mounts in our coupe, many years ago, we started to experience clutch chatter. You can cushion away the chatter by retarding the spark a bit more untill you get the car moving. This could save a lot of work and money.
 
Purdy and Steve;

I also have FAM's. I will try retarding the spark until I get on the move, but I don't advance it very much from a start as it is. How tight do you fasten the bolt on your FAM's?

Thanks for the input.

Dick
 
I don't think so !!! Any real model A mechanic will tell you, if the tip of the input shaft is worn very much it will cause the transmission to jump out of high gear. I can't imagine the tip of the input shaft being worn enough to cause clutch chatter. Theory can be all over the place but If the pilot bearing and input shaft was worn enough to cause clutch chatter, you probably wouldn't be able to keep it in high gear. It may have oil on the clutch or it may not actually be clutch chatter at all. Sometimes without the original solid rear motor mounts the engine will slightly jump around apon take off and this chatter is often reffered to as clutch chatter. Model A's dont have the anti chatter rods like the early V8' s and with closed drive the hole drivetrain will float if float-a-motor mounts are used.
 
if i remember correctly , they have a steel collar like the wish bone . tighten untill tight . if im wrong i do appologize . ive only wored on them twice . how is the tail shaft held ? mine is a 5 speed & it has a cross member to tighten to ............... steve
 
Purdy Swoft said:
I don't think so !!! Any real model A mechanic will tell you, if the tip of the input shaft is worn very much it will cause the transmission to jump out of high gear. I can't imagine the tip of the input shaft being worn enough to cause clutch chatter. Theory can be all over the place but If the pilot bearing and input shaft was worn enough to cause clutch chatter, you probably wouldn't be able to keep it in high gear. It may have oil on the clutch or it may not actually be clutch chatter at all. Sometimes without the original solid rear motor mounts the engine will slightly jump around apon take off and this chatter is often reffered to as clutch chatter. Model A's dont have the anti chatter rods like the early V8' s and with closed drive the hole drivetrain will float if float-a-motor mounts are used.
Click to expand...

Mr Swoft, you're probably right. Maybe one day I will get enough experience working on Model A's to be considered a "real Model A mechanic." Until then, I will yield to your expert advice and experience.

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