Clutch Chatter Diagnosis

[40B1930]

After 60 miles of shake-down drives, I am hearing clutch disc chatter with the trans. in nuetral. When I press the clutch pedal in to the point where the slack is taken up the chatter stops. After driving the car for a few miles the chatter is gone (maybe the grease on the new throw-our bearing thins after warming)?
1. All parts are new
2. Clutch disc was centered
3. Pressure plate rebuilt and fingers double checked
Could one or two fingers be off by .003-.005 and cause the chatter? I checked them twice but? Or flywheel warped? Thanks!

[Mitch]

I’m wondering if your hearing gear roll over in the trans. The throw out bearing is not moving until you depress the clutch. A little more info is needed on how far your depressing the pedal when the noise stops. What are you using for trans fluid? Do you have about 1” freeplay?

[40B1930]

I have been using the "600" oil from one of the major parts suppliers and the free play is right at 1"+ a small fraction. Should I try taking a half turn of play out? I have not tried that yet. The noise stops just as the freeplay is out and the start/contact of the throwout bearing.

[plyfor]

Had same issue though with v8 clutch. One finger was slightly off, and just slightly not enough freeplay as stated though thought I had 1".. Probably can reach inside the access cover and check the fingers.

[tbirdtbird]

what about the pilot bearing? That comes into play especially under the circumstances you describe

[Mitch]

So it sounds like the noise goes away just by having the throw out bearing roll against the fingers without depressing them. This would eliminate the finger adjustment and the pilot bearing, since the crank rotation is still locked to the input shaft

[Mitch]

You might just need a little lube between the clutch fork fingers and the throw out bearing hub.

[Mitch]

The word chatter can be misleading.. Chatter usually happens on take off
Letting the clutch out

[Mitch]

This is what I was referring to. A little grease between the fingers and the hub.. I’m thinking you have a squeak or a rattle type noise

[Mitch]

Pull the top inspection cover and take a peek

[old victoria]

had a problem like that, the owner had the T.O. bearing jammed off to one side of T.O. hub and not much free play, all kinds of bad sounds and a lot of chatter, ????

[40B1930]

I will pull the inspection cover tomorrow and report. Also, when I make my donut run at 7:00 am I will video the startup and capture what I'm hearing. I greased the new bearings when I had the motor out, I always worry about over greasing. However, when I broke the ring gear teeth (about 3 weeks) after doing the motor and went back in to replace the clutch disc, I may have wiped down the the hub, I dont remember.

[Patrick]

I'm wondering how long you have have owned this monster. Before having all this work done, did it have this noise ?

Your noise kinda sounds normal to me, these transmitters are noisy in neutral. But, I don't think I'd say that noise is a chatter. Its just a gear whirring noise.

[40B1930]

I bought this car three years ago with the understanding it had been "restored" in the early 90's. This noise is not normal. As I mentioned above, after a brief warmup and a few miles drive the noise stops and I'm back with my beloved Model A that's as new when it left the Ford dealership. It is a fun car!

Fast forward, I have gone through the entire car with the exceptions of the gas tank removal and paint.

For my driving purposes having a good clutch disc is imperative for ease of 2nd gear downshifting and smooth gear shifting. The new disc has been night day better (the old disc was glazed and "chattering)

The sound just started a few days ago and as I gain on the "clutch disc jargon" the noise is definitely different from the obvious chatter I was having with the old glazed disc.

Removing the trans inspection cover tonight.

[Patrick]

Hmm, OK. It'll be interesting to hear what you find.

[Tom Wesenberg]

Grease is good. Just don't get it on the linings. I had to adjust these fingers as they were quite a bit off. With the lock nuts it was an easy job.

Clutch Fingers New.jpg

[40B1930]

I definitely did not put any grease on the fingers for fear of it flying off onto the clutch disc. Tom, I checked and double checked the finger height and they were spot on. Mitch is point on that the sound I am hearing is NOT clutch chatter (I have really bad hearing at my age), he describes exactly what I was hearing on take-off with the old clutch disc that told me it was time to replace it. With the car in neutral and no foot on the clutch pedal - there's the noise. When I depress the pedal to the point where it starts to engage - the noise is gone. After warm up and a short drive - the noise is gone when in neutral and no foot on the clutch pedal (as if the noise never existed). I agree with you that you only need a few fingers to be ever so slightly off and you will have noise. However, I'm only guessing when I think about I have the noise when nothing is engaged, therefore, could it be that possibly even though I measure my free play at a solid 1+ inches, it may need a bit more? It is a quick test, so I will try it tonight. Tom - thanks for your note.

[Mitch]

Michael pull the inspection cover tonight and hopefully you will find the noise. Since you have the noise without touching the clutch pedal i'm hoping it is easy to locate.

[Chuck Sea/Tac]

Have you pulled the throw out inspection plate and looked in there yet? It seems you would be able to locate the source by doing that?

[40B1930]

Tonight after dinner ~ but please don't tell my wife!

[Tom Wesenberg]

When I bought my Model A it had a really bad noise, like a broken down threshing machine, and it turned out to be the bearing between the input and output shafts in the tranny. A couple rollers were toast, and you wouldn't believe how much racket that made. Tranny Bad Bearing Roller.jpg

[DaWizard]

Hey Tom, just how many of those output shafts do you have available for measurements?

The tranny I pulled with the engine had a second gear howl, and come to find a long bearing in the front, so it has 2 long, 1 short. I would like a few other measurements to see if mine is different in that length since in my earlier days we always ran 2 long, 1 short.

[Tom Wesenberg]

None apart nor spare tranny parts at the moment.

[40B1930]

Just looking at the photo brings back memories of what my ring gear looked like after it failed a few months ago! Lost three teeth on that day.

[1crosscut]

Try to find a youngster with good ears to help find the noise.

[40B1930]

No time in last night's schedule - Honey-dewed. With the butterflies I have now wondering what the issue is, I will be after it after work tonight. My wife has excellent hearing and is a terrific help. She has been put on alert status. Praying for it to be something really simple...like needs grease. Until then ~

[Mitch]

Watch your fingers

[my 29 ford]

getting wheel wobble what should i look for ?

[Mitch]

You might want to start a new thread for your problem : )

[40B1930]

Left the office early today to put an end to my noise problem.

The discovery:
1. Everything well greased
2. Hub spring correctly in place
3. Pushing the clutch pedal down to where the throw out bearing makes contact with the fingers is about 3/8-1/2" travel.
4. I noticed two fingers that were making contact with the bearing well before the others (about a 1/32-1/64 variance). AND THERE WAS THE NOISE AT IDLE IN NEUTRAL WITH CLUTCH OUT!

My thoughts: as I have commented, after warmup and a few miles drive the noise is gone for the day. Additionally, the car shifts as it should, downshifts from 3rd to 2nd smoothly at speed and upshifts tight and smooth with zero grind. I feel there is a chance all the new parts may need a "breaking-in" time and the noise one day will take care of itself. If not after 4-500 miles, this winter I will pull the rearend and trans. again and this time rebuild the pressure plate myself.

I spent a bundle of money equally distributed among three parts suppliers who I believe work very hard to service our hobby and purvey the highest integrity. My only comment to them: consider having those items that you rebuild inspected, tagged and signed off so QA and QC is assured.

I admit I was hot under the collar and looking to place blame, however, I'm the mechanic at task here, not the parts houses. I should have caught it. My Dad marched me up and down the shop telling me to check everything and then di it again!
I assume all responsibility for the pressure plate in regard that I bolted it up to another flywheel on the bench and it measured just fine. I repeated the procedure during installation and somehow missed the difference in the two fingers.

I have the inspection cover sitting here on my book stand to remind me of lessons from my past. And oh yeah - I will still love our awesome hobby and my love of all cars in general this winter when I am dragging out the rearend and trans again!!

[CSPIDY]

It’s kind of a shame but a good mechanic always remembers his mistakes and seams to forget all the good work he has done.

[Tom Wesenberg]

As the clutch disc wears, the fingers move towards the rear of the car, which means the pedal freeplay gets less. Just increase the pedal freeplay to one inch, and the noise will likely be gone.

[40B1930]

Thanks Tom - I'm on my way out to do as you suggest. There is a variance between pedal freeplay and throwout bearing freeplay. About 3/8" on my setup. Many thanks for your comment. Michael

[40B1930]

Tom - you knew what the problem was as did Mitch. Kudos to both of you for your patience until it soaked in. 1" of free-play is a "starting point" like most things Model A. Further adjustments or fine tuning are often required. Lesson learned! Thanks again.

[tbirdtbird]

Mitch, it is late and I am tired. Given what he just reported, why is it this can't possibly be the pilot bearing?
Under these circumstances , tranny in in N, the input shaft is spinning, and thus riding on the pilot at the forward end, and the tranny input bearing at the back end. I suggested this might be a possibility and you said no. Maybe I forgot to take my medication LOL

It is hard to believe that 2 fingers 1/32 out would cause this.
Dave

[Mitch]

Dave I just saw this post sorry.

When the clutch is disengaged, (pedal depressed) the transmission’s input shaft and the engine’s crankshaft are rotating at different speeds. The pilot bearing allows for this difference. This is why a faulty pilot bearing makes its most noise when the clutch pedal is completely depressed and the clutch itself is completely disengaged.
When the clutch disc is engaged the crank, pilot and input are spinning together.

I'm sure you know this and we are maybe just reading each others posts wrong

More Meds please!!

[tbirdtbird]

Thanks, I do know that but it was too late last night for me to think straight!

[Chuck Sea/Tac]

Haven’t there been posts, regarding adjusting the pressure plate in the car. If so, it wouldn’t be too bad of a job, to only do two fingers.
I’m with Dave however. If the two fingers aren’t touching with the clutch out, then how could it make noise? It seems far more likely it’s the pilot bearing.
did you measure the transmission input shaft for inner bearing fit?

[Patrick]

The finger adjustment can be done while everything is in the car. It takes some time in some cramped quarters, but, beats taking it all apart. As mentioned, the freeplay at the pedal should be in the 1"-1.5" range. I'd still like to know what the noise is.

[Mitch]

Same here
It made the noise without touching the pedal. Originally stated he had 1" of free play

[40B1930]

After reading Tom's message late last night, I went out and adjusted the pedal another 1-1/2 turns out and that was too much (about 2" of free play). I re-adjusted it with a 1/2 turn back in and the pedal is now at 1-1/2" free play. It was too late to start the car, however, I am heading home now (1:30 pm PST) to start the car and adjust a couple of fingers. I'm not a believer that it's the pilot bearing, everything is new - BUT, one never knows! lol I will report back later tonight. Thanks everyone for your help.

[Mitch]

Without depressing the clutch the pilot bearing is rotating as a unit with the crankshaft and input shaft. I like 1" of free play myself

[40B1930]

Im sitting in a purring model A right now. The extra one full turn out was the ticket. My pedal has about 1-1/2 of free play now. I will be sending $50 to VFF tonight on behalf of all the good suggestions and Tom for getting me under my car at 11pm last night. Thanks everyone!!

[Mitch]

I'm glad your noise is gone but it's still not making sense to me unless it was some sort of linkage rattle. Poss by moving the adjustment stopped it