What would cause a 1989 Honda Accord lxi 5 speed transmission to not go in fifth gear?

* Worn synchronizer rings: The synchronizer rings are responsible for matching the speeds of the gears before they mesh, allowing for smooth shifting. If the synchronizer rings are worn, they may not be able to properly align the gears, causing the transmission to grind or pop out of gear.

* Damaged shift forks: The shift forks are responsible for moving the gears into and out of position. If the shift forks are damaged, they may not be able to properly engage the gears, causing the transmission to pop out of gear.

* Bent shift linkage: The shift linkage is responsible for transferring the movement of the shift lever to the transmission. If the shift linkage is bent, it may not be able to properly engage the gears, causing the transmission to pop out of gear.

* Low transmission fluid: Low transmission fluid can cause the gears to overheat and become damaged, leading to the transmission popping out of gear.

* Damaged transmission case: A damaged transmission case can allow transmission fluid to leak out, causing the gears to overheat and become damaged, leading to the transmission popping out of gear.