Clutch fluid formula :

12 ounces Ford type F automatic transmission fluid, 12 ounces power steering fluid, 12 ounces Hudsonite, 4 ounces kerosene.  Mix all components and use 6 ounces per refill in clutch.  (this is a way to extend the Hudsonite, you have on hand, and  a less expensive way of refilling, when several refills are required)

Another:  from Brandon Wight

On clutch fluid, you have a few options. One use some from WRP, or mix your own 30wt non detergent oil and k1 kerosene. That's a 50/50 mix for 6oz.

Flushing cork clutches:

make solution 4 parts tri-chloral-ethane and one part acetone, available at drug stores.  To flush-drain clutch, refill with flushing solution, start engine, with transmission in neutral, depress and release clutch about 100 times at various engine speeds, drain and refill with clutch fluid mixture.
 

Clutch chatter solution suggestions   by Doug Wildrick 317-862-4171 

 
The fingers on pressure plate must be correct height, from top of the cover, with the new disc  installed.  This measurement should be no more than 1.450, and the fingers should be set at .010-MAX ., variations between them.  If this isn't done  correct, the clutch will probably chatter. 

DON'T FORGET THE FLUID IN THE CLUTCH

Following items to check for clutch chatter (other than pressure plate and clutch Disc)

*   Check for cracked bell housing (usually passenger side of bell housing starting at cross shaft)

*   Input shaft excessively worn at pilot bearing end.

*    Input shaft (twisted and/or excessively loose-front transmission bearing excessively loose)

*   Clutch cross over shaft bushings (usually worn excessively)

*   Alignment of transmission with engine (bell housing bolt up surface free of dirt)

*   Back  of block cleaned and dowels secured in place.

*   Engine and transmission mounts are good and solid. (not soft-very important for proper clutch operation.

*   Flywheel resurfaced  correctly and torqued at correct specs with clean flange on crank and flywheel. Use soft setting Permatex and seal flywheel to crank flange (thin coat)

*    Throw out bearing fork not worn (what did old throw ought bearing look like-worn spots in bearing housing)

*    Engine tune (is it running properly)

Above items are not necessarily in order-each vehicle is different!