Got a 98 tj 4.0. New clutch, maybe 5k miles old. engages really late in the pedal stroke. Tried manually bleeding the slave for 10 or so minutes, no change. Put washers between slave and bellhousing to test, drove great for a couple miles of in-town driving, now it's back to engaging late. Any input?

Did you replace the clutch master or slave cyl. when you installed the new clutch ?
If not, my $$$$$$ are on one of them being bad.

no? not sure why that would be the problem though. I may try replacing the slave with a hydraulic cylinder though...so I could at least bleed it normally

why reinvent the wheel. replace the whole shit and shebang like everyone else and run it for another 100k miles or until it goes bad again.

yes, try the master and slave replacement as a COMPLETE, pre-bled system. if you did a new clutch disc/pressure plate and throwout brg just 5K ago then it is probably the master and slave. the slave is non-bleedable just like i have on my 94 AX15 (external).

These don't seem to be the symptoms of the typical slave failure. The usual complaint is it will no longer disengage the clutch. And seeing as I don't have $170 to drop on the jeep this close to christmas, this is the mod I was looking at:
http://www.universityofjeep.ca/Tech/Clutch/Clutch_Slave_Repair.htm