Although I don't see the potential for much change due to temperature, there is another condition that may be of note. Those input shafts are prone to twisting, especially in a case where the clutch has been "grabby" or "chattery" in the past due to the factors already covered. The twist occurs starting immediately behind the disc hub (because that's when there is sufficient torque applied to do the damage), dis-allowing rearward movement of the entire disc when attempting to release the clutch. The disc then fails to "float" in the space thus created, as it should, but stays in continuous contact with the flywheel. That drag makes it nearly impossible to shift into a non-synchronized gear (first/reverse)and makes hard shifting in the others. Worse yet, you are prematurely wearing out the synchronizing clutches in normal driving and especially if you force it into one of those from a standstill.
I've seen many twisted shafts, so it's worth a look......except that you can't see it without removing the trans, but I suspect that's where you're headed anyway. A shop that claims to "work on old cars" isn't the right choice unless they are learned in the idiosyncrasies of the Hudson cork-insert, wet clutch. It's a whole different animal.
Frank

The most common cause of this problem is rebuilt clutches which still had moisture in the corks.Corks are wet when installed and require a lot of baking to get it all out. If there is moisture,the corks swell up when they get hot and all the clearace disappears so it can't release. As soon as it is cold again everything is OK. If that is the problem, changing the disc is the only cure. I hope the guys doing cluches now fully understand the importance of this.

I think I am just going to pull the clutch and have it rebuilt by Wildrick. At this point not sure if the fluid is even the issue. But I moved the car for sweep day yesterday, around the block shifts no problem (cold)

I recommend you send it to the guys in Texas.

Is it possible to switch it out for a regular "dry" clutch??

Absolutely not, unless you can some how transplant a complete flywheel, dry disc and pressure plate assembly.

A conversion to dry clutch is definitely possible:

IF (a big if),

we can believe the story in (I think) WTN about the 1916 Hudson (first year for Super Six) that the owner had restored and fixed up for The Great Race. One of the modifications mentioned is conversion to a (later model) Chevrolet (dry) clutch.

Something else went wrong, as I recall, and the 1916 car finished on a trailer. Wait until next year !!

I don't know, but suspect the transmission input shafts match in diameter and number of splines. Flywheel adaptation might involve re-fixing the doweling and bolting of the flywheel to the crankshaft. If that matched too, the dry clutch conversion was a piece of cake.

But why do it at all?

The Hudson clutch is plenty good, as shown by the Hornets' race record, among other records. Get it right, as the factory tells how, and go on. Solve the real problem (something wrong with clutch build up) instead of an invented problem (the dry clutch conversion).

Wait.

At this point we have a lot of conjecture about what's causing your problem.

When one has a problem, one looks for the most likely cause first. That's the essence of troubleshooting. In this case the most likely cure would entail the easiest, fastest and cheapest solution.

So: have you tried draining and refilling the clutch oil yet? This procedure involves maybe 15 minutes and a $5 can of Hudsonite or ATF. The problem may lie elsewhere, but this is the first thing you should try.

If you discover that the clutch WAS filled with oil, [u]then[/u] we can proceed to the to next most likely cause, and the next, in logical steps, following a process of elimination.

Thanks gentlemen, thought maybe it was an easy swap for a dry clutch that fits the spline.
Anyway I am checking fluid as first steps. A friend here in my local HET chapter has provided me some Hudsonite fluid. I will update my troubleshooting/progress over the next week. :side:

Well the clutch did indeed have fluid, so I finally pulled it this week. Not sure if you experts can tell anything by looking at this photo, but either way it is getting sent off this week to Ron Fellows for a rebuild.

After you put it together, but before you put the transmission back, check to make sure the three clutch fingers are all the same distance from the rim of the clutch cover. This is necessary to get smooth operation of the clutch. There are various ways to adjust them. However, if they are really far off, it may be necessary to have the pressure plate worked on.

The corks are badly glazed, and would probably be okay with a good clean-up with lacquer thinners, providing they are around the correct thickness of .180" overall.

Thanks for the info. Some of the corks look smashed, or crushed beyond the shape of a perfect circle. What does "glazing" do to the functionality?

Glazing causes the plate to stick to the flywheel, and also causes shuddering when letting the clutch out.

A nasty looking disc on an absolute scale. It's not necessary to be a Hudson guru to know this is at best a rebuildable core.

Compare to a new disc, and ask yourself if this disc ought to be expected to work like one in good condition. Answer: (Don't peek) No.

Would anyone buy a disc that looked like this one, expecting it to make an improvement in operation ? I kind of doubt it.