I have a 98 xj 2wd with the 4L engine. The manual transmission is
currently in neutral (ie not in any gear) and I can't shift it into
gear (any). The clutch feels normal. It happened quickly, one
stop light it worked, the next, would not shift. Any idea what is
wrong, and what I need to do?

 

well, luckily this hasnt happened on my xj, but it did happen to me on my old yota. Sounds to be about the same thing that happened to it, i replaced the slave cylinder and clutch before i found out that it was something connected to the petal. I carried mine to a mechanic and he said that it was not the clutch itself, but something that engages the clutch...you get what i mean? i cant remember what exactly it was but it had to do with the clutch petal and such. hope it helps

 

Hm. I'd almost be willing to say you've dropped the Nylon bushing on the bottom end of the shifter...

To check:

1) Remove the shifter ****
2) Remove the shifter boot
3) Remove the "underboot" around the shifter. (NB: Removing the centre console about now as well is strictly optional. If you're not used to working down in a hole, it's not a bad idea...)
4) You should see four screws around the shift tower, holding it to the transmission. I believe they're all M6 screws, and take a 10m/m socket (if I'm wrong, they're M8 screws - 13m/m socket.)
5) Lift the shifter out of the hole.

You're going to look at the bottom end of the shifter (the bit inside the transmission) and check for a Nylon bushing around the finger that sticks into the transmission case. That bushing is there to prevent galling and wear, and it does wear out (and sometimes fall into the case.) Any outfit that handles OEM parts should be able to get a new bushing for you - check Morris 4x4 Center or TeamCherokee (Google Is Your Friend.)

You can also manually shift the rails through the open hole - just be sure you put them back in Neutral before you try to put the shifter handle back in. Due to the lever action of the shifter, the "pattern" of the shift rails is opposite the pattern on the ****. They may be shifted using a longish screwdriver, using standard clutch action (this will allow you to see if the shift rails themselves are frozen - if they are, you're pulling the transmission. Either a detent ball & spring has come loose and screwed things up, or you've got bigger problems - probably on the countershaft.)

Installation of the shifter handle is the reverse of removal. However, if the shifter rails won't move manually, don't bother putting the shifter back - since you'll need to remove it to pull the transmission anyhow.

 

i would say it is your clutch, i had the same problem when i swapped in a AX-15 about 2 months into it, swapped the clutch and slave...i was good to go.