Pressure Plate photo and what is problem??

[Bruce in southern OH]

Have owned this 31 Tudor for about 2 years, driving was limited because of clutch chatter. (it has gotten worse) I am going to take car to the MARC meet in June of this year so I removed the transmission and pressure plate today to see what problem is causing the "shake the head lights off" chatter. This is what I found, disc side to fly wheel looks like new, everything clean. The disc side towards pressure plate has skid marks on the pressure plate. Let me know what you think caused the marks on pressure plate. Car drove fine and shifted fine, just could not go from a start with our "voilent" chatter, thanks
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The dark streaks are clutch disc material, not heat marks
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Fly wheel and pilot bearing all look new, clean and smooth
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[redmodelt]

Off hand I would venture a guess, the clutch face of the flywheel was turned down and the lip was left unturned or the pressure plate was not adjusted properly. How do the fingers on the other side look? The springs may not have enough pressure, that one at the bottom looks funny or are not even in pressure allowing the pressure plate to bounce.

[Bruce in southern OH]

Redmodelt, do you remember the depth of lip to flywheel face, I will check tomorrow, I remember this happened to a friend of mine. Machinist did not do both surfaces and it would slip bad in third. My car would pull fine, but you never know until I check depth, thanks for the info, will see if someone post correct measurement.

[ford3]

well it looks like the clutch is slipping, not enough free play, at least 1" to 1 1/2" free play at the clutch pedal, mis aligned pressure plate fingers, bad or warped clutch judging form the blue spots on pressure plate,, what ever the problem is the clutch is definatly slipping

[1937pickup]

Is that an Asian re-pop? If it is get your hands on a Ford original and send it to Fort Wayne Clutch for a proper re-build. They may have one on the self they will sell you without a core.

[redmodelt]

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Don't have the depth at hand. If they cut X off the face of the clutch the same amount is needed off the lip. Hope someone chimes in.

[Patrick L.]

I'd first recommend putting a dial indicator on both the flywheel and clutch housing. Flywheel should be within a few thousands and the housing less than 10. And install the disk and pressure plate and measure the finger height. They should be 5/8" or 11/16" and all within .002".

[Tom Wesenberg]

I recall the depth being listed as 1.123"

Do you also have pictures of both side of the disc?

As Patrick said, be sure to check the flywheel disc surface for in and out wobble, and check the flywheel housing for alignment at 9, 12, and 3 o'clock. I try to get them under .007".

[Ron W]

I think that chatter is often the combination of pressure plate fingers being uneven and a bad throwout bearing. Ron W

[Mitch//pa]

you have it apart and only want to do it once
replace the pilot bearing, throw out bearing, clutch and pressure plate, and resurface the flywheel...
dont half ass it

[James Rogers]

Stock depth of the flywheel face to ring top is 1.125". I find if the flywheel is ground by clamping to the table by the outside ring it will grind out of level. The flywheel has to be clamped with a spacer inside the crank recess. I use a 4" double bearing race for a spacer and don't have this problem. I ship flywheels all over the US and would go broke paying return shipping if I didn't do it right. I also do stock flywheels locally and have never had a return.

BTW, I got the measurement above from a NOS flywheel that has never had a clutch or pressure plate bolted to it. Not a factory reject but a true NOS.

[Bruce in southern OH]

Thanks James Rogers and everyone else, I will go to garage today and take measurement depth of flywheel, check flywheel alignment. Then I am going to bolt old pressure plate to a spare flywheel ( after I check depth ) with new disc and check the measurement of finger height. I have a new pressure plate I purchased from Tam's a couple of weeks ago, will also check the new pressure plate finger height on this new PP. I will report back with findings this evening,

[Bob/Kansas City]

Definitely replace the pilot bearing while everything is out. A bad pilot bearing can be a cause of chatter. You might also check the diameter of the nose of the trans input shaft where it slips into the pilot bearing. The input shaft pilot bearing surface should be .668" / .666". If it is worn smaller it should be replaced..... and of course that leads to a complete trans rebuild etc.. etc... ask me how I know.

[Bruce in southern OH]

Here is what we found today, the depth of flywheel in tudor car is, flange to flywheel 1.125". Next we also have a flywheel from a car/truck that measures 1.25" on workbench and we checked the old disc and it measured .364 and the new disc measures .386 thick. We placed the old disc and pressure plate in flywheel, tightened up and measured the distance between top of pressure plate and fingers, it measured almost a 13/16". Next we placed the new clutch disc and pressure plate in flywheel and it measured a heavy 7/8". ( I could tell that it was going to be high because the last 3 pressure plates we have installed there was about two threads in adjustment screw on fingers showing above top of nut.) Now the hard part, ( this is new $90.00 dollar plus pressure plate ) we tried to loosen the adjustment screws to change the top of pressure plate to finger distance to 11/16". The screws were "Staked" and seemed to be rusted under nut on the ones we could move. Three out of the Six screws we had to side cut nut and free up to remove!!!!! Robbed the nuts from the old pressure plate ( probably still good ) and installed on the special adjustment bolts. Took about 3 hours of non stop work to get all six adjusted to 11/16"!!!( thanks DON ). Don and I are pretty sure that the poor adjustment of flywheel fingers lead to the clutch slipping and making the clutch disc deposit small amounts of material on pressure plate. NOW, like I have been told CHECK THE NEW CLUTCH PRESSURE PLATES !!!! I am sure back in cars past someone picked up the pressure plate and installed, this is when the trouble started, I was just on the receiving end.
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Pressure plate adjustment device, checks distance, continuity checker for fine tuning, and a location for dial indicator! This was the old pressure plate in flywheel showing gap between correct setting and existing finger setting.
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New pressure plate checking fingers, heavy 7/8"
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[Don]

Are the special bolts and nuts on the PP finger adjustments available ????? Had to just about destroy a couple on Bruces PP to get them loose. Guess a guy could make them if nothing was out there .

[Bruce in southern OH]

Tom W. and everyone else, could or would you explain what the pressure difference would be if you set fingers at 7/8" versus 11/16" and also the difference it would make in the clutch pedal position in car. I would like to have information to give supplier so that it is not just me giving information about why just having fingers close and even does not work. It needs to be correct height for car to operate correctly. ( installed clutch disc, pressure plate and transmission this evening, will connect drive shaft, pedals, brake rods, battery, etc. tomorrow, hope to test drive Monday, thanks everyone )

[Tom Wesenberg]

Actually the pressure on the plate remains the same as long as you have some freeplay between the throwout bearing and 6 fingers. Since this can be adjusted, you shouldn't notice any difference in pedal height either. It's just that the 6 arms are designed to move through a certain arc, and setting them at 11/16" puts them in the arc they were designed to move in.

[Don]

Are you sure the pressure stays the same? Put a spring between finger and thumb and squeeze ,the more you compress the stronger the spring gets.

[Tom Wesenberg]

The springs aren't changing length when you turn the adjustment nuts.
The nuts move the levers in and out.

[Bruce in southern OH]

Tom, how about this question, don't you think that you would set up Model A pressure plates to Model A specs if sold for Model A's? Also how much would the thickness of different clutch disc affect the finger height?

[Tom Wesenberg]

The 6 adjustment bolts pull the pressure disc up, so measure the distance from the bolts to the fulcrum, whih is the notched part of the levers, then compare that distance to the distance from the fulcrum to the point of contact for the throwout bearing. Let's just say it 1" for the first measurement and 2" for the next, then a disc .100" thicker would move the levers .200" closer to the flywheel.

I would think the rebuilder would use a metal plate the same thickness as a new Model A clutch disc to set the 6 fingers to the standard height. I would always check though, just to be sure, because it's so easy to do when the tranny is out. I wonder if the same pressure plate is used for some other cars?

I just went to the basement and measured the distance on a spare pressure plate.
It's about .675" and 2.513", so the ratio is actually about 1 to 4. So a clutch disc .100" thicker would move the arm about .400" at the point where the release bearing contacts the arms.

[bobH]

For whatever it's worth... I've got a PP - free, if anyone wants it. Shipping might be the killer.
It came out of a 34, and I've been told it's same as mod A - it looks the same.
BTW, interesting discussion, and thanks for the info. JMO

[Bruce in southern OH]

HERE we go! Installed everything back in car yesterday at 2:30PM EST., From that point on it was not good. First started car and placed in gear, everything fine, but still have front floor board out and took inspection plate off and pilot bearing running. This is where the trouble started, adjusted to where bearing would not run and car would not go in gear. (raking). Tried everything, (hours going by) Like the TV show I called a couple of friends (doctor Don P. and Professor Dave M.) both had words of wisdom and I did try them. Took a break for dinner (1/2hour) Returned to start measuring parts in transmission through the inspection plate opening, same as original transmission I had in car. The transmission I placed in car was one I had for years that was clean and green and all new parts. I am going to clean up the old one but for time I used the clean/green one. We even discussed drilling shaft to move clutch lever to get more travel. NOW what I found at about 8:00PM was the clutch lever on newer green transmission measured plus/minus about 3 3/4"long hole to hole and the old lever on 30/31 transmission measured 2 5/8" plus/minus hole to hole. With much work I got the two transmission levers changed. Adjusted clutch and I NOW HAVE A WORKING TRANSMISSION, PILOT BEARING WITH 1/4" GAP, ( 9:30PM!!!!!!!!!!!!!) Took for drive in the dark on couple of back roads, seems fine. Anyone know of the use for longer lever???? 28/29?

[Tom Wesenberg]

Was the lever an original part, or was it homemade for easier clutvh pedal?

[larrys40]

Sounds like you have one of the earlier arms
They make for an easier clutch but your adjustment range is very narrow
It would have worked probably but your free play was too much it sounds like
If it was one of the original arms they are hard to find
Thx
Larry s

[Tom Wesenberg]

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Larry, that was my first thought also, but I didn't think the multiplate arm was that much longer.
I'll have to measure both of mine to check the difference.

[Bruce in southern OH]

It is an original arm Tom, I drove car all day up to this point, seems like everything is going to work fine. Really a pleasure to drive car with no shutter, traveled to a large flea market, Wendy's, gas station, friend's house to look at a electrical job and home. Just took car to garage to take front wheels off, will inspect brakes and pack front bearings. Then work on the rear wheels next week and change oil. If anyone has a temp gauge for a Model A I would appreciate information, need to watch engine temp., getting ready for French Lick. Going to drive car to Church tomorrow, everyone have a great Easter!!!!

[Bob C]

I went and measured some clutch arms and the longer one
is for a multi-disc clutch.

Bob

[Purdy Swoft]

Here is the three clutch arms. the long one on the right is the multi disc style the center is later 28-29 style. the arm to the left is 30-31 They will all interchange. the 28-29 arms are used with keyed release shaft.

[bobpo1]

Originally Posted by Mitch//pa

you have it apart and only want to do it once
replace the pilot bearing, throw out bearing, clutch and pressure plate, and resurface the flywheel...
dont half ass it

If you have it broke down already, I'd have to side with Mitch and maybe keep this one as a back up and have it re-turned. Could be wrong, but I would think this the best solution. At least replacing the parts would get you back on the road where all 'A's belong this time of the year.

[Mikeinnj]

Originally Posted by Purdy Swoft

Here is the three clutch arms. the long one on the right is the multi disc style the center is later 28-29 style. the arm to the left is 30-31 They will all interchange. the 28-29 arms are used with keyed release shaft.

And then there is this one sold by Brattons....

[Purdy Swoft]

Yeah its also longer and reduces the amount of pressure needed to depress the clutch. I put that one on my roadster. Its steel and the way that its made, I can't see it ever breaking. The original clutch arm is forged but a lot of us know that they do break. The release shaft and arm was still in good shape on the roadster so I removed it as a whole and saved it so I could go back original if I ever wanted to. The new arm didn't want to fit the new release shaft so I broke out the adjustable reamer and fitted it. It works well and I like it.