89 camry sv21 5 speed manual trouble selecting 3rd gear
 

hi all,

am new to this site so not sure if im posting in the correct spot but here goes.
i am having trouble selecting 3rd gear in my 5 speed manual gear box in my sv21 89 camry after trying to teach a learner driver how to change from second gear to third and they didn't back of the accelerator while doing so. all other gears are fine. now as i move the lever up to third then release the clutch it jumps back out of gear some of the time, it seems to stay engaged if i force the gear lever up hard into position before releasing clutch or hold the lever in position while releasing clutch but if i just place it into gear normally it jumps back out. can anyone help me with this problem?

thanks.