Clutch disk question

[Oldav8tor]

I'm doing a bit of research.... has anyone ever seen any documents or other evidence that Ford would press a small "dish" into the shape of the small clutch discs used in Model T clutches? I've come across some info that indicates that may have been done but heard from others that such could not have been the case. Supposedly the result of such a treatment results in a much better neutral without adversely affecting the operation or longevity of the clutch. Is that something there would be info on at the Benson Ford?

[Jerry VanOoteghem]

Tim,

I'd bet that the Benson Ford would have the clutch disc drawings, but I'm not sure that they have re-opened to the general public.

My guess, which counts for nothing, is that they were flat. Very curious to see what you end up finding out.

[TXGOAT2]

I don't know if Ford dished Model T clutch discs, but I believe it was done in many cases to make engagement smoother and more progressive. I'm pretty sure the Model A single plate clutch discs were dished slightly.

[browning]

I have had the pleasure of restoring a number of Fordson model F tractors which used a clutch that was similar to the Model T setup and shared the same problems. When the clutch plates wear against each other for a long time they actually mate to a near perfect fit which when glued together by cold and congealed oil almost refuse to release from each other making the clutch temporarily useless. The benefit of the tractor is that the sliding gear transmission gave a free neutral which made them able to be cranked when cold without jacking up a rear wheel. If by some miracle you manage to get a Fordson started in the winter cold, the problem then becomes how to get the danged thing in gear. The secret is to allow the engine to warm up for a while, reduce the engine speed to idle, make certain that “ all is clear” ahead, depress the clutch pedal, and finally use whatever force is necessary to rake the gear shift lever into high gear. If you are successful and don’t stall the engine the tractor will take off in a manner similar to when they open the gate at the rodeo and you are off, even with the clutch depressed. The forward movement will continue until the clutch pack finally submits to the torque and comes free, which seems to depend on the weather and the whim of the tractor gods. Many a farmer has met his Maker and the back wall of the barn at the same instant. One of the ways to prevent all that fuss is to intentionally deform the clutch plates prior to assembly by laying them on the face of an anvil and giving them three or four well placed whacks with the ball end of a ball peen hammer. The assembled clutch will then release and probably slip for a while if not perfectly done. Of course I would never recommend using that procedure on a Model T but for a tractor it sure beats riding one through the end of a building!

[RGould1910]

From the wear patterns I see, it sure appears the discs were dished. It may be just the outers, that I don't recall

[Alan Long]

There are a few of us here in Western Australia that deliberately bend steel plates in the Model T Transmission.
I believe a piece of 2” pipe is the tool to create the dish. We are basically duplicating the metal plates used in a wide range of modern Automatic Transmission. Generally theses are in the clutch packs that apply / release multiple times such as the high gear clutch on the Borg Warner 35. The dished plates soften the 2 -3 shift plus when released they aid the separation of the plates giving a full disengagement of that clutch pack. Same would apply with the Model T High Clutch. Only a few plates 3 or so are dished. Personally I use the Turbo 400 Biscuit coloured plates and flat steel plates (all) in all 3 of our T’s with great success. The “Ford o Matic” Transmission of the late 50’s / Early 60’s is a hydraulic version of Henry’s T Transmission!
Just my opinion. Alan In Western Australia

[TXGOAT2]

Be sure the clutch is properly adjusted. Use Marvel Mystery Oil in the Fordson to ease starting and inmporve clutch action . Start the engine in neutral, warm it up until the crankcase is warm, then try puting it in gear with the engine running as slow as possible . If the tractor has a clutch brake, be sure it is working properly. If competent help is available, stop the engine once it is warmed up, then put the tractor in high gear and hold brakes on, then start the engine while holding the clutch down.

[Jerry VanOoteghem]

Any dishing or distortion I've ever seen in a clutch disc has always appeared to me to be caused by warpage from overheating. I have not reused those discs.

[DanTreace]

Those Ford clutch discs are flat from the factory, no dish.

There was a suggestion by Murray F. in his Ford Owner articles of penning worn plates to help for a better free neutral, but that was for worn really thin plates.

Of interest is a compensating disc offered in 1925, but only seen this one adv, likely the item didn't work out in practice.