Outer Limits 4x4 Board

Hi, recently I went for a drink (84 blizzard), and ended up with about 30cm of water in the passenger side, (and about 10cm on driver's side). Was stuck for about 10 minutes before getting pulled out. Within that time, and only realised later, the cabin wasn't the only place the water got into.
In short I drove about 100Ks back home and notice grey ooze from the gear box.
Next day I flush, as best as I could, the gearbox. I will still need to do the transfer and diffs. I then went for a drive around the block.
The gears unsurprisingly changed nicely and smoothly and better than ever before, and no more graunching noise. However I only changed into 5th once and in the next straight when I tried to put it into 5th, nothing.
It was like neutral, no noise and no resistance when trying to engage 5th.
Prior to the swimming lesson 5th gear had a slight hum, so maybe that was a sign?

Anyone experienced this?
Any help would be appreciated, 4th at 100km is really annoying!

thanks

Havent had that exact problem, but have had water in the gbox twice and it dont like it , you be a bit lucky and just have to replace 5th gear.

mmm maybe ur 5th gear went out of place on the shaft in the gearbox. had this sorta experience in a ford falcon, no 5th, feel as it's in neutral turns out that the circuit clip came out and the 5th gear went spinning along the shaft away from the driver gears
got it fixed and was very glad to have 5th back