1929 multi plate clutch radial wave driving disc

[147 Franklin Airman]

Can anyone describe or show me what the radial waves in the driving disc look like on the 1929 multi plate clutch?

My clutch is either off or fully on, very difficult to get it to slip.

[raydurr]

About 35 years ago I remember my grandfather describing clutch grab in his 1929 Buick. His solution was to stop up the drain slot in the bell housing  and fill the bell housing with " coal oil". He would let sit for a little while , push in and out on the clutch pedal a few times and finally drain the fluid from the bell housing. He said that clutch would be smooth as silk for a year or two afterwards. I have considered doing this myself lately. I am not suggesting this as a remedy, merely passing on a story of what occurred probably 85 years ago. Good luck!

[147 Franklin Airman]

2 hours ago, raydurr said:

About 35 years ago I remember my grandfather describing clutch grab in his 1929 Buick. His solution was to stop up the drain slot in the bell housing  and fill the bell housing with " coal oil". He would let sit for a little while , push in and out on the clutch pedal a few times and finally drain the fluid from the bell housing. He said that clutch would be smooth as silk for a year or two afterwards. I have considered doing this myself lately. I am not suggesting this as a remedy, merely passing on a story of what occurred probably 85 years ago. Good luck!

Thank you for this, I was almost thinking about adding a little oil as I remember motorbikes having multi plate clutches & they were always in oil.

[edinmass]

A clutch is either dry or wet.........I wouldn’t even consider or comprehend why you would add oil to a dry plate clutch........unless a possible fire is on your wish list. 

[jps]

You may already have this info, but if not, here are the 2 pages from the 1929 shop manual on the clutch:

 

John

[michealbernal]

The factory service manual for the Allis Chalmers model M tractor recommends washing both the master and steering clutches by installing a plug in the clutch compartment drain hole and adding kerosene to the compartment.  It then recommends driving the tractor while releasing and engaging the clutches for about 10 min.  It then recommends draining the compartments.  This model tractor was built from the 1930s into the mid 1940s.  

[147 Franklin Airman]

2 hours ago, jps said:

You may already have this info, but if not, here are the 2 pages from the 1929 shop manual on the clutch:

 

John

Thanks JPS, yes I have the manual. The radial waves are not clearly visible 

[147 Franklin Airman]

56 minutes ago, michealbernal said:

The factory service manual for the Allis Chalmers model M tractor recommends washing both the master and steering clutches by installing a plug in the clutch compartment drain hole and adding kerosene to the compartment.  It then recommends driving the tractor while releasing and engaging the clutches for about 10 min.  It then recommends draining the compartments.  This model tractor was built from the 1930s into the mid 1940s.  

Thanks Michael. This is very interesting. Does it say why it would need washing out or what the advantage would be. I will try & search for more info  

[Rock10]

Wouldn't kerosene leave an oily residue that would cause the clutch to slip?

[Old26Buick]

Is this clutch like a 27 Standard. I rebuilt mine myself

[147 Franklin Airman]

3 hours ago, Old26Buick said:

Is this clutch like a 27 Standard. I rebuilt mine myself

If its a multi plate then probably yes, did the lining plates have the radial wave in them? 

[ramair]

I thought I would add to the comments about tractor clutches, tractors  worked in a very dirty environment compared to cars, also the tractor in question I believe to be a tracklayer and they have two additional clutches which are the steering clutches.  I recall flooding a steering clutch on a cat 20 with kerosene and the procedure involved constantly pulling on the friction clutch until it operated properly.  I believe the reason we did it was the dirt kept the clutch engaged and it was hard to turn.  I do not believe that washing the Buick clutch would help smooth it out

[27donb]

I'm confused as to what "radial waves" in a driving disk refers to.  Is that term from a manual? 

 

I thought multi disk Buick clutches had driven disks and friction disks.   What are radial waves?

[147 Franklin Airman]

9 minutes ago, 27donb said:

I'm confused as to what "radial waves" in a driving disk refers to.  Is that term from a manual? 

 

I thought multi disk Buick clutches had driven disks and friction disks.   What are radial waves?

If you look at the 2nd picture sent by jps you will see the driving discs that have a radial wave in them. My guess is that they are bent (for sake of words) in order to create a high & low area which would reduce the friction until fully released by the clutch pedal . It's this radial wave that I'm trying to confirm.

[27donb]

8 hours ago, 147 Franklin Airman said:

If you look at the 2nd picture sent by jps you will see the driving discs that have a radial wave in them. My guess is that they are bent (for sake of words) in order to create a high & low area which would reduce the friction until fully released by the clutch pedal . It's this radial wave that I'm trying to confirm.

 

Thank you for the clarification. 

 

I understand what you mean, like a spring wave washer, the plate itself has high and low spots. 

 

Those pages from a 1929 shop manual show what appears to be the same basic clutch as my 27.  To me, the plates all look flat, no wave.  My 27 clutch has all flat plates as well. 

 

I could be wrong on your application.  It just seems that if some of the plates did have high and low spots by design, those spots would overheat and blue due to the concentrated friction on such a small area. 

 

I think all the plates, are flat. 

[147 Franklin Airman]

5 hours ago, 27donb said:

 

Thank you for the clarification. 

 

I understand what you mean, like a spring wave washer, the plate itself has high and low spots. 

 

Those pages from a 1929 shop manual show what appears to be the same basic clutch as my 27.  To me, the plates all look flat, no wave.  My 27 clutch has all flat plates as well. 

 

I could be wrong on your application.  It just seems that if some of the plates did have high and low spots by design, those spots would overheat and blue due to the concentrated friction on such a small area. 

 

I think all the plates, are flat. 

Hence my question, what is a radial wave? 

[tonybuick]

could the splines be worn making the plates unable to slide in or out easily causing the plates to hang up so it isnt a smooth action a bit on or off when working the clutch pedal

[147 Franklin Airman]

3 minutes ago, tonybuick said:

could the splines be worn making the plates unable to slide in or out easily causing the plates to hang up so it isnt a smooth action a bit on or off when working the clutch pedal

I never thought about that. The driven discs are brand new. I would need to check the hub splines. Thank you for your input. 

[jps]

I think that "radial wave" simply refers to the "lobes" or "teeth" that exist on the periphery of each disc plate.  They are called "radial" because they are like rays originating from the center of each plate every few degrees.  However, the disc plate facings themselves are flat, as it says here in the manual:

The "wave" exists only at the edge where each of these spaced rays end - sort of like on a U.S. quarter coin that has small ridges on the edge - and not on the facings themselves.

 

John

[Oldtech]

I agree with John, The discs should be flat, if there is any appreciable wave to them they won't release. Multiple disc clutches drag anyway. Check the grooves in the flywheel for nicking as that makes the discs hang up.  Careful attention with a die grinder will help .

[147 Franklin Airman]

13 hours ago, jps said:

I think that "radial wave" simply refers to the "lobes" or "teeth" that exist on the periphery of each disc plate.  They are called "radial" because they are like rays originating from the center of each plate every few degrees.  However, the disc plate facings themselves are flat, as it says here in the manual:

The "wave" exists only at the edge where each of these spaced rays end - sort of like on a U.S. quarter coin that has small ridges on the edge - and not on the facings themselves.

 

John

I agree in that the "unlined discs" should be flat, it's the lined discs that look "waved" in the photo which is causing me to question this. 

[147 Franklin Airman]

57 minutes ago, Oldtech said:

I agree with John, The discs should be flat, if there is any appreciable wave to them they won't release. Multiple disc clutches drag anyway. Check the grooves in the flywheel for nicking as that makes the discs hang up.  Careful attention with a die grinder will help .

Just as a point of interest, the reason I replaced both the driven discs & the driving discs is that the clutch was grabbing before & the ones I took out were worn. 

[jps]

Here is a link to an older forum post for a 1926 Buick clutch, which in turn has another link to more clutch info.  This old post shows the mid-late 20's Buick linings to be flat, and the outer edges to have a "wave" pattern.

 

 

Otherwise I can get the definitive answer in about 10 days when I go to visit a guy that has a rebuilt Master 1929 clutch assy sitting in his basement - I can examine it and take photos to verify.

 

John

 

[147 Franklin Airman]

Thanks John, very interesting read of  the old post. 

"

 the outer edges to have a "wave" pattern.

"

I still cannot visualise the wave

[jps]

OK, finally I found something that answers the question clearly, and I was wrong.  The driving plates are NOT flat and they DO have a wave to them - described here and shown pretty clearly in the photo below (notice the non-uniform gap between the driving and driven plates, and the text below the photo) from the 1929 Buick Detailed Specs book, page 12:

 

 

John

 

[147 Franklin Airman]

52 minutes ago, jps said:

OK, finally I found something that answers the question clearly, and I was wrong.  The driving plates are NOT flat and they DO have a wave to them - described here and shown pretty clearly in the photo below (notice the non-uniform gap between the driving and driven plates, and the text below the photo) from the 1929 Buick Detailed Specs book, page 12:

 

 

John

 

That's a lovely clear picture & a description that I've been looking for. Thank you. It goes against a lot of theory but obviously this is my problem. Now I have to decide how much of a bend to put in the plates 

[jps]

Contact Tony Bult, at tonybuick272829@gmail.com.  I guarantee he knows how much curve to put into the plates, and/or who can do it for you.  He has restored dozens of 28-29 Buicks.

 

John

[147 Franklin Airman]

On 8/28/2021 at 3:20 AM, raydurr said:

About 35 years ago I remember my grandfather describing clutch grab in his 1929 Buick. His solution was to stop up the drain slot in the bell housing  and fill the bell housing with " coal oil". He would let sit for a little while , push in and out on the clutch pedal a few times and finally drain the fluid from the bell housing. He said that clutch would be smooth as silk for a year or two afterwards. I have considered doing this myself lately. I am not suggesting this as a remedy, merely passing on a story of what occurred probably 85 years ago. Good luck!

UPDATE.

I took the plunge and added 5 litres of ATF to the bell housing and after a brief soak, drained most of it out and to my surprise the clutch is lovely and smooth. Tried it on a step hill and it bites nicely. I also noticed that when on an incline it is now easier to get in and out of 1st gear when before it was impossible.

It is now a test of time to see how long it lasts.

Thank you so much for your advice Raydurr 

[raydurr]

I am happy to hear that you reached a simple solution to you clutch problems. These clutches are durable but difficult to replace. Old timers had some crude yet simple solutions to problems such as this. Have fun!

[Hubert_25-25]

So now that you have oiled the clutch surface, are you getting any slippage in any of the gears?  I had a Datsun 240 Z and they made aftermarket replacement clutch discs with very little brass in them.  Once you got into 4th gear and stood on the gas the clutch started to slip.  High revs without expected forward motion.  Had to pull the clutch out and replace it with an OEM disc. 

Edited February 4, 2022 by Hubert_25-25 (see edit history)

[Vintage wonders]

I have tested on a steep incline but not at high speed. I am waiting for most of the oil to drain away & will test again. 

I'm fully ready to have to reline the discs again but hoping not. 

[147 Franklin Airman]

Not sure where "Vintage Wonders" came from. I must have set that up years ago but never used it.

Took a long drive today at speed and up a long incline, not clutch slip at all so very happy for now.