I do remember reading how some folks have rebuilt the clutch. As I remember, over time, the oilite bearing is driven down the shaft, allowing the tension pin between the two halves of the clutch to displace - thus not allowing a good clutch between the plates.
Folks have replace the bearing with a bronze one that has a shoulder that can prevent it being forced down. However, the shoulder adds height that has to be compensated for by reducing thickness on a positioning washer.
I read the article/forum casually - but I'm pretty sure that's the jist of the topic - keeping searching - If you can't find the parts - I'd suggest a machine shop, not a mechanic.
And, here's the only other information I've gleaned from various forums. Hopefully something can help get you onto the path...
"Ordered from Lippert Components, South Bend 574-537-8900
Kit, Leveleg Gear Replacement and Hardware (66591), Item number 678826
included the gear, washer, and the pin for the gear."
2008 Phaeton 36QSH, Safe-t-Plus, Quadra Bigfoot
2017 Jeep Cherokee Trailhawk w/ flat tow wiring mod.
Blue ox, BrakeMaster + BrakeAway, diode lights and charge.