I have a 2000 XJ with 240k miles, and every once in a while I will lose my overdrive, and it doesn't go above 3rd. Usually on the highway. When I shut off the engine and turn it back on it usually comes back, then does it again at a random time sometime later. I have adjusted my TV cable, but the cable where it connects to the throttle body is badly frayed, and down to only one wire at that spot. Could this be the issue?

 

Well, down to only one wire sounds like its gonna go any time soon. So, address that before it leaves you stranded.
ATF level and quality good?
No problems in shifting manually?
OD Shift solenoid would be my next guess.

 

I changed some fluid not too long to see if that was the issue, with no change. Haven't shifted manually, I'll check that next. I was under the impression that solenoids either worked or didn't, not sometime work and sometimes not?

 

I've had the same problem for over a year now. Hasn't gotten any worse. I have been told it is the solenoid my plan is to wait until the m
Next time I drain the fluid and drop the pan to replace all the solenoids.