VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1929-1932 Clutch disk

At what point is a 1929 coupe clutch disk worn out? Mine is 9/32" total thick with 1/32" left before its down to the rivet heads. How thick is a new disk? Filling Station doesn't show any replacement friction disks for this year, is there another source? If a local shop can do the work, what type of friction material do I ask for? Which kind doesn't grab? When the car used to run about 45 years ago I recall that there was only a small range of pedal between slipping the clutch and fully engaged, is this typical of this year of Chevy? Will glass bead blasting the bits of rust off of the pressure plate and flywheel damage the working surfaces?
Bill

Hi Chevysix,

I'm not that far yet, but very interested how to solve this, maybe Bluezone, Arvid, knows what to do here, he redid a '29 completely some years ago. He is now doing a '25 truck and from what I saw, factory new. He also has a '26 redone and a ’32. have a look here. http://www.chevroletnorge.com .
Good luck and let us please know what the solution was.


Richard

How different is the clutch disc for a 28 and a 29'? I have one that is supposed to be a NOS for a 1929 and I was told it would fit my 28' I can measure it, if I can find it!

The Chevrolet parts book indicates that 1928 is different than 1929. :( :( :(

Bill:
When I redone my 1932 the clutch, pressure plate, and flywheel were a mess. I did glass bead all parts, and had the working surface of the flywheel and pressure plate turned. I have completed my project enough to drive, and the clutch seems to work fine.

Chevysix. (and hi Richard)
If your -29 have the orginal disc,this have no springs in the center. I will recommend to use a newer disc with springs to avoid rattles.You can use disc up to -37 or my be newer.

If you do this,you most countersink the screw in the senter of the flywheel. Thickness of the new linings on the pictures are 3,50 mm,and total thickness are 10,33 mm. I have used spring disc in my -25 and -26 truck and my -29 car, and the clutch are very smooth on all cars.
From Norway
Arvid
http://www.chevroletnorge.com

Ok, the part numbers for the 28 and 29 clutch discs are different, but does that mean they won't interchange or even that there is a differance?

The 1928 clutch disc was not carried over to 1929 according to the parts book. The parts that are the same for 1928 and 1929 are indicated as such in the 1929 parts book.

Several years ago when replacing the cluth disc on my wife's 1972 Vega we discovered it was very similar to a 31 clutch. Difference the 72 had anti chatter springs. We sat the new 72 clutch aside and used a 31 Clutch and it worked great till we sold it 3-4 years later. I know of others that have put a 72 Vega clutch in their 31's-32's... If the 29 disc is interchangable upto 37 the Vega Clutch should work. You might check a parts house ( NAPA ) for the Vega clutch.
.....What goes around comes around!!!!!!!!

If anyone happens to try a 72 Vega, let me know. I'll need to redo mine or try the vega in a couple of months. Thanks.

Thanks, a clutch is a clutch but a part number is something else!

Chevrolet ('32) has 10 splines. Vega ('71-'72) has 14 splines.Did I miss something? :confused: :confused:

After looking in my 1935 Parts Book, I see the 31 Disc with facing #836367 is only applicable to a 31 AE. I am only passing on from experience from what I did. I'm not sure how many splines a 31 has, must be 14 as that is what a Vega is supposed to have. Since the original posting is for a 29,This will not work for ChevySix.

The 1931 clutch disc has 10 splines, not 14. Also 1929-31 passenger cars used the same clutch disc (836367).

1933 Chevy added the cushion-mountd hub. 34 they increase the cushion-hub spring rates to 90 lbs. 35 they chaged the disc to smooth radial wave design with 5 high spots to lessen clutch chatter. 36 was a carrier over from 35. 33-36 plate have 10 splines.

Arvid and everyone, thanks for the feed back. Is the difference in performance of a disk with springs, over the original disk, worth the effort of counter sinking the flywheel bolts on the 29?
Bill

Hi Bill
I mean indeed the are worth the effort to do this improvement.You will have a much better clutch if you do this change. But, your choice . :) :) :)
Let us hear what the other boy's suppose.

Regards
Arvid

If the clutch plate is in good condition and the wavy metal disc is still wavy then the original clutch plates will give similar performance. The wavy metal disc causes the friction material to touch the pressure plate and flywheel in a progressive manner that reduces the chatter. It is critical for the flywheel and pressure plate to be smooth for best operation.

I have never found that adding a later clutch plate with springs did much better and surely was not worth the extra effort. It has proved to be a problem when a spring breaks and locks the clutch.

I agree that if all original design clutch parts are in good condition then the clutch should operate as originaly designed and be quite satisfactory.However I think the reason the engineers changed the design was for the reason of trying to improve it.I think it is a case of preference of originality or not.As far as the spring dampened disc it is interesting to note that it is still being used on heavy trucks.

The latest comments raise a new question. Looking at the Master Parts List it appears that the friction disks are free floating and are not riveted to the disk. Is this true? Do I have original equipment since mine is riveted? If it is riveted then should the disk and friction material both be wavy? Mine looks pretty flat. How much wave should I measure?
Bill

They should be rivited.The original 1929 was flat.The 1934 had what they called a warped disc.The 1935 was a five segment disc with waves.The 1935 was the late replacement for 1932 and up.Some replacements for 1931 and prior could be waved.

The dampening springs in the hub were (are) more for torque (in high gear) vibrations than smooth engagement.

The friction material was riveted to the metal disc and the material was flat, not wavy.

The very early (first 6 months) 1925 clutch linings were free floating and not attached to the disc. The later units were attached with the rivets.

Where can you purchase the clutch lining and rivets?

The NOS discs that I have still in the box have wavy metal discs. Maybe they are later manufacture with the original numbers or the originals that are removed have the wavy plates flattened by heat or pressure or both.

I am suprised that the metal part of the clutch disc assembly might have been flat. Seems like a step backward as the leather cone clutches (F series and 490) had springs to put a wavy surface to the friction surface. If the springs lost their tension the the clutch tended to grab instead of smooth action. To remove the high and low wavy surface would make the tendency to grab much higher.