can't shift to 5th gear
 

it happened today when I was driving on the freeway,
no weird sound or shake before fail .
it can't shift with engine on or off ,
clutch ,master ,slave cylinder works .
1st ,2nd ,3rd ,4th and reverse all works.

after I got home , I took off the shifter and check the bushing and check the
shifter , it looks normal to me .

any suggestions?
thanks

OK - reverse works so it's not a jammed plunger in the extension housing.
That leaves the possibility of a stuck 3rd/5th interlock pin, or some bits of the 5th gear cluster are jammed up.

This is a long shot, but with the engine off, try shifting directly from 3rd to 5th a few times.
If it's a stuck interlock pin, that may help.

Another long shot, jack the left rear, tranny in neutral, grab the tire to rotate the wheel back & forth to bang the drivetrain backlash.
With some luck, any stuck parts in the tranny output shaft will come loose.

This is old school shit, but it won't hurt to try..