Another Trans Issue

96 XJ, AW4, new one on me, never seen it before. I've had some minor neutral safety issues, usually just when the motor is cold. But today the tranny kind of popped once or maybe more of a crunch when I started it up hot and shifted to reverse, then no reverse. Starts up fine in Park or neutral, so the cable is likely OK. Neutral is now a forward gear and as far as I can tell I have no neutral anymore, reverse acts kind of like neutral, but the XJ refuses to roll in R unless I shut the motor off.
I hope this makes sense to somebody, it sure doesn't make any sense to me.

Check the mounting of the shifter cable on the transmission. It has an adjuster and it may have broken.

Update, the problem has morphed a bit, I now have reverse but it feels like the brakes are locked up, it backs up but it really strains. Neutral is still a forward gear.
I pulled the trans fuse, no change, I even unplugged the TCU no change. Disconnected the linkage cable at the trans and tried shifting at the trans no change.
Drained the fluid, it was pretty nasty. No bits or pieces in with the drained fluid.
I'm having some issues getting the two pieces of the dipstick tube to separate. I unbolted the pan, wiggled it a little left and right and could see the two parts of the dipstick tube rotating independently of each other, they are loose and twist, but don't seem to want to separate or come apart.

I tried shifting from reverse to drive at a round 1500 RPM (brakes locked), to see if I might build some back pressure and dislodge a blockage in the valve, body (works on Chevys) didn't help any.

Time for a Beer back at it tomorrow. Cross your fingers for me and wish me luck. Tomorrow I should have another set of hands to help me with the dipstick. Maybe my dipstick son knows some dipstick tricks.:spin1: