No reverse and no 5th gear

The 5th gear feels like there isn't anything there no engaging. The reverse will not engage, like the gear is blocked or closed.
Thanks for your time
rich

Thanks again
rich

Lost reverse over a period of 4 days. Sometimes went right in to gear and then slow to engage and now completely lost reverse. When Shift lever goes to reverse you can hear a faint hissing noise fom underneath, stops when moved to park or neutral, have found a small vacume hose that had popped of and reconnected that helped it engage for one day then completely lost reverse. Fluid is at proper level and clean with no burn odor, never had a problem with trans, purchased new in 95.
Could the filter be clogged or some simple common problem?
Thanks

Ok heres my question i have and 88 nissan pickup 2.4 nap-z 4x4 5 speed with approx 193000 on the odo, when i put my truck in reverse and disengage the clutch it kicks out of reverse but not before it grinds and like it sounds like the gear it not meshing or something it doesnt do it in any other gear though other than that it doesnt have any problems but i t wont let me back up or very little i dont know what to do to fix it i am very mechanically inclined but it finding the time to do it which is why i would rather know what im looking at to fix any help would be great thanks matt

Check your fluid, chance are that isnt the problem but, one possibility is your slave cylander is leaking. Another cause is a bad clutch. Check for the leak first, then Id say do a, or have some one do a clutch inspection.