'87 FX16 GTS 5th gear popout

[xaxxat]

My FX16 transmission has started popping out of 5th gear. I'm using a bungee cord to hold it into 5th.

Is there a simple solution to this problem or am I looking at a rebuild / swap deal?

Thanks

[xaxxat]

I found a solution to the 5th gear problem:

http://www.mr2.net/trackdayqueen/fithgear.htm

Further reading has convinced me that my input shaft bearings are about worn out, so it looks like a swap or rebuild is definite.