Multi-Plate Clutch Issue

[jrbartlett]

Does anyone specialize in diagnosing problems with multi-plate clutches? I have a 1919 Locomobile clutch with 20 plates (dry) that sometimes fails to disengage -- it's not stuck on the flywheel, because it will disengage one moment, and then fail to disengage 30 seconds later. Any specialists out there? 

[edinmass]

Is the issue not or cold? Or both? Ten to one.......incorrect material on the friction plates........or is it all steel? 
 

Also.......transmission alignment and input shaft binding could cause it.........loosen up all the bolts so there is just a little bit of slop and run it around the neighborhood a bit........

Edited February 25, 2022 by edinmass (see edit history)

[jrbartlett]

I'll give it a shot. Issue is hot or cold, progressively getting worse. Plates date back at least to the 1972 restoration. I plan to get under the car this weekend. Thanks.

[edinmass]

Here is a strange clutch effect that is common.......the exhaust manifold is on one side of the car, causing the transmission and bell housing to expand more than the cooler side.....thus causing heat induced thrust clearance issues. That is why many people have a harder time shifting a car without clashing the gears when the chassis is at full operating temperature. Certain cars we drive we mill the bell housing or transmission housing about 7-10 thousandts on an angle.......presto....shifts fine when hot......but it's fussy when cold. 

[George K]

Here are excerpts from a circa 16/17 Locomobile instruction book. I remember you stating you had a large Locomobile literature collection.

Might be redundant. Locomobile changed clutches rapidly during their development.

[jrbartlett]

Yes, I've been studying the diagram. Thanks.

 

 

[George K]

In a dry clutch wear occurs on the contact face of the drive and driven plates. There is a hardness difference between disk and the stationary slide blocks to resist wear. But over time they create wear notches on the drive blocks and reduce the drive tangs of the plates.

As Ed states the diminishing of clutch material contributes lost of the plate stack height. Multiple dry disk clutches get hot pretty fast. The heat causes warping. Saw blade steel was used to help with that issue.

Locomobile dry clutches have a double row ball bearing deep in the clutch with no way to lubricate without complete removal.

Make sure the sliding release collar has smooth and complete movement.

Only way to inspect is to remove the whole clutch intact and get someone who can properly open the clutch and not get killed or harmed in the process. Best of luck, George 

[jrbartlett]

Thanks for the insights. I've been in touch with a shop in California that has worked on Loco clutches and that was recommended to me by several owners of these cars. I may take either the clutch pack or the entire car out there for service. I had identified the spring as a serious risk just from its fearsome look in the diagram. Although I do have a press, and did work on heavy stuff while in the Navy Seabees, I've not worked on a clutch like this before. In the meantime, I had also identified the release collar as possibly not traveling its full distance. I'll investigate that further. Thanks for the insights. 

[edinmass]

 

One of the hardest lessons to learn in the car hobby, is to take your problem to the right shop........since you can count the shops that are familiar with this clutch on one hand of a fingerless man, bringing to to someone with experience makes you start 50 hours ahead of the game. Generally speaking, on a problem like this.......I would be prepared to make every disk new.

[Jubilee]

 In modern two plate pull type clutches,( think heavy duty

trucks) intermittent disengagement always means a

piece of broken spring floating around.

  Just a thought. I know nothing about 1919 clutches.

 

[Ittenbacher Frank]

Dear James,

all that has been said before makes sense, and the various design improvements over a comparably short period of time show that Locomobile was not 100% happy with the earlier versions.  When you read what the driver has to do and what lubricatns to use for proper treatment of the leather cone clutches, then it becomes clear why they invented the dry clutch. For safe transmitting the high torque of a model 48, you need either one plate of very large diameter (friction area) and a very strong spring (which has certain disadvantages), or many smaller plates and comparable less spring force. You must also take in consideration: The operators manual states: The car can be started in high gear. (see the manual shown above). Many people didn't have much driving skill yet, and owners of such cars expected the chauffeur to drive smoothly, less shifting was probably expected, and the manual states several times that the car can climb nearly every hill in high gear.

I would like to share my limited experience with Loco clutches: They work well on both of my cars, until now I have not found a reason for dismantling and inspecting them. I have driven the 1921 Sedan in hills, on highways, in Cologne's heavy traffic jam, no problem at all. Always disengaging well (and noiseless shifting into first due to the clutch brake), and never slipping under load.

But: I mentioned before I live in a region with many hills, the road in front of my house has a 16% slope. Once we had an appointment, I had planned to take the Loco, but we were already too late. I wanted to use that trip as a test drive because I had re-adjusted the carburetor float level once again. But this time it was obviously too low: when getting into the slope the engine stalled several times, and when it finally kept on working it had no power because it was too lean. I had to increase the engine speed more than usually necessary. Under these circumstances I had to re-start in the slope several times within a short period of time. This obviously made the clutch heating up. Then shifting became difficult, and when I stopped at the first cross road, I could not engage first gear without scratching. Ok, engine off, first in, starter, and off we went. And now comes the interesting part: Already at the next crossing, app. 1/2 mile away, the clutch worked again as usual! Until now I never experienced that clutch trouble again. I believe the plates deformed (like a dish) when warm, and flattened againg when cooling during driving.

I think you should check the temperature of your clutch housing when driving. Usually it stays quite cool. You can try driving without the floor board and use an infrared thermometer while in motion. Maybe the pedal adjustment is not ok? Or the linkage is not releasing the pressure completely? Or the clutch brake is too tight? Whatever, if it is not spinning freely somewhere, you will notice the heat increase it that part.

Another bit of experience, but only second hand: My friend with the red Loco race car had cutch trouble already several times. He told me that the last time one of the lining rings broke, two pieces wedged together and made the clutch stuck. End of the race. He found a shop in Nürnberg specialized in brake and clutch repairs. They were able to make the new lining for him according to one original sample and the disk size. Now it works again.

Good luck!

[Ittenbacher Frank]

Dear all who contributed to this thread already and might be interested in the multi-disk dry clutch of the Locomobile M7 (model 48). Finally I got a good reason to inspect the clutch on my 1917 Loco tourer: Because I wanted to remove the flywheel anyway, and because I had once heard a shrieking noise while declutching, which I wanted to understand, and a bit of curiosity as well...

Yesterday was the right time with bad weather and not too occupied with other jobs.

Firstly I took the clutch off the car. One useful remark: You must remove the two square driving blocks from the shaft, otherwise the coupling doesn't clear the transmission yoke. It is not nice to hold the clutch over your head for a long time, figuring out why it won't come out. The whole unit weighs 30.1 kg (67lbs).

Edited February 6, 2023 by Ittenbacher Frank
correction (see edit history)

[Ittenbacher Frank]

Next, I studied the documentation. There are several design evolution steps, mine seems to be the type for 1917 models, as shown in the operating manual dated April 1916.

[Ittenbacher Frank]

Then I prepared tools for safe dismantling: three special bolts, 3/8-20 BSF or UN thread on one side for the clutch side and M8 on the other side (any threaded rod with an outer diameter slightly smaller than 3/8" will do...)

Because I didn't know how much the large spring would expand until the pressure was released, I made them far too long. Now I know: the spring travel is 56mm (2 3/16"). If you can find threaded rod with 3/8-20 BSF or UN threads, three pieces of 3" each will be ok.

I replaced three of the six original bolts with the special bolts, equally spaced, tightened them, removed the other three original bolts, lubricated the special bolts thread's, then slowly and symmetrically released the spring pressure. This worked very well.

(sorry, some of the photos turned upside down)

Please note: the last photo shows the condition before cleaning.

By the way, friends of the previous owner told me: He never dared to open that clutch. That means, nobody looked into it for at least 36 years.

Edited February 8, 2023 by Ittenbacher Frank
added photo and text (see edit history)

[edinmass]

Adventures in 100 year old technology! 

[Ittenbacher Frank]

Now the clutch came apart. I was surprised to find everything quite clean, nearly no dust. I removed all discs one by one and found:

- 8 steel disks with teeth on the inside, teeth width is 16mm (5/8").

- 8 steel disks with teeth on the outside, teeth width is 19mm (3/4").

- 17 floating fabric discs are in between, inner diameter app. 165mm (6 1/2"), outside just very slightly less than the housing which is 196,6mm (7 3/4"). They obviously contain a lot of copper.

- the thickness of all steel disks is 1,6mm (1/16")

- the thickness of all lining disks is app. 3mm (15/128"mm): one is 2,9, two are 3,2mm and two are 3,4mm.

- the complete set of disks is somewhere between 79,0 and 79,5mm (3 3/8").

It is interesting to note: The guides for the disks are exchangeable if worn (they are riveted to the housing), but they look nearly new, not worn at all as you know it from motorcycle clutches. I assume they are very hard.

The double row bearing near the flywheel turns free and nice, I left that in place. Now I am confident that this did not cause the noise.

Assembly went uneventful, just the same procedure in reverse.

[Ittenbacher Frank]

One final hint what I learned from my friend Lothar (he owns the red 1916 speed car): Once he had the clutch locked up (no disengagement any more) because one of the fabric discs broke in half, one part wedged under the other parts, increasing the total length of discs. You better don't try to bend them...

Edited February 6, 2023 by Ittenbacher Frank (see edit history)

[Rusty_OToole]

An old friend named Charlie Mahoney solved this problem on his Indian Four motorcycle. They had a multiple disc wet clutch. Looking at the plates with the tabs on the outside, he drilled a small hole in the tab and stuck a piece of neoprene O ring thru the hole. This acted as a spring to push the plates apart. He did this to every second plate. No more sticking clutch.

 

At the time I rode English motorcycles that also had wet clutches that were supposed to run in motor oil. I filled the primary chain cases with automatic transmission fluid, and had much less problem with the clutches sticking. The only time they stuck, was when the bike had been sitting for several days, the cure was to pull in the clutch and kick the starter over to free the clutch before starting.

 

Whether this info is any use on your old cars, I have no idea, I am just throwing it out there.

[dodge28]

Just a thought. Years ago I worked on a tranny that had a wet clutch made of wine cork. If the transmission oil became too thick with use I drained the oil, filled the tranny with alcohol and washed the cork, refill with fresh oil. Sometimes the cork will wear to the point where it had to be replaced. The cork had to be cut into small pieces and inserted in the holes of the disc and then sanded level. I also rode Triumph with wet cork clutch. Frequent oil change did the trick.

[Ittenbacher Frank]

Maybe I should also add: This clutch which I opened for inspection works very well. It disengages completely, grabs very smoothly when starting, the shifting is nice (if you know how to deal with the sliding gear transmission), and has never slipped so far. Just for information.

[Ittenbacher Frank]

Dear Specialists who have worked on a Locomobile clutch brake mechanism before, I have one question:

- Do the two universal housing halves slide on the transmission yoke or is it supposed to be tight?

The two halves I am referring to are shown as number 20 in attached drawing. The yoke for transmitting the driving force is number 23, the shaft 9 is connected with the yoke by two sliding blocks 22. There is a woodruff key on the yoke 23 which prevents turning of these two halves and its slot allows an axial movement of the universal housing of slightly less than 1/4" when the two halves are not fully tightened.

The reason for my question is the function of the clutch brake: When I push the clutch pedal, then at the last bit of its travel the clutch brake shall slow down the transmission yoke. But what happens at this last bit of travel, between "brake lining grabs" and "pedal it at its very end of the travel"? I have the impression that the clutch brake is overloaded then, the brass lining shows score marks already, and sometimes I heard shrieking noises while driving.

On my other Locomobile (the series 8 Sedan) the design is different: The clutch brake is supported by 6 bolts with springs. When you push the pedal to its end, then the springs are compressed a bit. These springs define (and limit) the pressure on the brake lining.

On this 1917 model I found no spring. The more you press the pedal, the higher the pressure on the brass lining.

Any suggestions?

[Ittenbacher Frank]

here are some photos of the parts mentioned before.

[Ittenbacher Frank]

Just to give an update on my question " Do the two universal housing halves slide on the transmission yoke?"

I got a feedback from my friend Lothar: On his 1916 speed car it is fixed, no axial movement. Same brake arrangement as on my car.

Same feedback came from a friend in the USA, with a 1919 Sportif. No axial movement. Here the clutch brake design seems a bit different: You can adjust the gap between throw-out-bearing collar and universal housing by means of a thread.

Anyhow, I will try one thing as a test:

1. I made 4 shims (2 on each side, cut from 0.2mm brass foil = 1/64" each side) and put them in between the two halves, now they slide freely without slack.

2. I made a spring washer, see the photos: a flat washer which I bent in one axis. If I push the universal housing towards the transmission against the shoulder, the spring washer becomes flat. When I release the pressure, the spring washer pushes back the universal housing by approximately 5mm (3/16"). Instead, I left the open washer out, which you see on that piece of wood on the right, beside the spring washer which is the one on the left.

I will report how the clutch works with this set-up.

 

 

 

Edited February 22, 2023 by Ittenbacher Frank (see edit history)

[Ittenbacher Frank]

I noticed that someone had welded the ends of the fork which pulls the throw-out bearing to the back. Not a nice job, rough and uneven. The mating surface on the bearing housing was already worn to some extent. I reworked both parts by welding, then grinding the fingers and milling the housing. I checked the parallelism on the lathe and found it ok. See the result.
 

 

 

Edited February 22, 2023 by Ittenbacher Frank (see edit history)