Worn synchonizer?
If a 2000 Jeep Wrangler suddenly loses power in 5th gear, it might be a problem with the speed sensor on the transmission. This sensor regulates when the Jeep will shift or should shift.
Your synchro is going bad.
A 2000 Jeep automatic that is not shifting correctly after it gets hot might have something wrong with the speed sensor that is located in the transmission. The speed sensor tells the transmission what gear to shift into at certain speeds.
your shift lever bushings are bad, easy fix.
Stick shift, yes. Automatic, no.
idler sensor!
If it will shift when the engine is off, but not while it is running your clutch is not working
In automatic transmissions the second to third syncronizers always seem to go bad first, the syncronizers are worn, bad or gone. This is common in these transmissions. Also you might check your trans fluid level, sometimes a low level will cause the transmission not to shift correctly.
depends on tire size and gear ration
There are several things that can cause your 2005 Jeep manual transmission to shift hard between first and second gear. The most common cause is a malfunctioning shifting fork.
it is probably your shift lever bushings, but check the rubber seals and carpeting, sometimes they put pressure against the shifter making it pop out of gear.
Does it grind or is nothing there? if it grinds, the shift rail is probably broke or a syncronizer is bad. If theres nothing there, the gear has failed. Either way, it's gotta come out.