1988 Cabby Slipping/popping out of gear?

Hi, Posting this on behalf of a friend in the US, he tried to join the forum to post himself, but on registering the site blocked him out?

Anyway, here is the problem..described by him.

Any advice appreciated, cheers Ian

"Nice to find this forum, i have some questions for the experts here while I restore my 1988 VW Cabriolet Convertible.

I have a Transmission problem that is a serious issue, i need to know if anyone knows what it could be and if i have to pull the trans or not to fix it.

It first started slipping/popping out of 4th and 5th gear at while cruising, not doing any crazy driving or anything just driving down the road.  I first thought it was the linkage being loose and not securely selecting the last to gears,, so i tightened that up , but it still continued.  about 3 weeks later I drove it 1 more time it popped out of 5th gear again but wouldnt stay in at all unless i held it in position, then it finally just popped!!!  5th Gear is GONE  there is nothing there at all now,  but the rest of the trans still works and no more popping out of any gears not eve 4th where the problem was first seen.

Im sure i will have to tear it open to find the problem but does anyone have any idea what this could be?  Knowing before hand will really help get prepared how to fix it before i dive in and tear it out.

Thanks GrnCrkts"

this happens if the gearbox oil is low, 5th gear is probably trashed now. you can get access to the 5th gear pair by removing the end cap where the green cover is, only a few bolts. the 5th gears can be replaced easily in situ, hopefully if you're lucky it;'ll only be 5th that has gone. if any of the other gears have been damaged then its a gearbox strip down or just replace the box.

loads of info here from a fellow yank:
Welcome to BrokeVW.com

HTH

Thanks for the reply

Info passed along!