Rated-XJ

I've got a 96 manual XJ that disengages gear while driving in all five gears (even in 4 lo & PT) at exactly 3000 rpms... every gear, same rpm. Once it does this, popping the clutch like you were trying to pop-start any man tranny re-engages the gear. Of course only if I'm @ 2800 or less rpms when I do this.. can anyone provide so insight here?

BwanaBob

Does it move the shift lever out of gear into Neutral, or does the shifter stay in the
gear's position?

Can you go past 3000rpm or at all?

Does the clutch ever slip at any other times?

How many miles on the pressure plate/clutch? Maybe the pressure plate springs are
getting weak.

Rated-XJ

For the most part, no on all counts.. it's the weirdest ****. The lever always stays, making the pop-clutch recovery instant (just drop your foot, snap it back up). No go past 3k.. the entire drive experience becomes a stutter when you try to stay at, or exceed that RPM... cluctch has yet to slip.. I actually wheeled it a few nights ago and while wheeling (low rpms obviously) she did great.. trying to get home I again had to mind the rpms.

BwanaBob

Something is making the pressure plate release from the disc,
and then stay released. It's not just a slip, after which the pressure
would return against the disc on its own without having to manipulate
the pedal.

Normally that would be the release/throw-out bearing pushing against
the pressure plate springs causing it to release from the disc and stay released.

Since the slave cylinder moves the release bearing, you could try replacing
the slave or the master/slave ensemble. Do you know when those were last
changed? I have a 98 and am on my third master cyl.

Another idea to throw out:
Do you know when the clutch disc/pressure plate set was last changed?
Was the flywheel machined at that time? (The factory manual says
that should not be done as it modifies the contour on the flywheel
which can cause disengagement. Not saying that is your problem
but it is a possibility.)

Anyone else have any ideas?