From your symptoms....
Ist gear is bad..
1/2 slider is bad if 1st is bad..
4th gear is bad..
3/4 slider is bad if it pops out
3/4 hubs are all bad if not repl with updated ones...
Rebush the gear carrier housing so the mainshaft bearing will stay in place.
Rebush case where 1/2 relay lever sits so there will be enough throw to get
into 1st or 2nd.
Need I say more??? (because there is more...) Your guy should know this
stuff if he knows that particular tranny without being asked

Any name brand gear oil generally works well if it changed on a regular
basis.
Good Luck
Daryl of AA Transaxle
(425) 788-4070
aatransaxle.com
86 Syncro Westy
Zetec in the trunk
----- Original Message -----
From: "AD Felder" <dieseldoofus@YAHOO.COM>
To: <vanagon@GERRY.VANAGON.COM>
Sent: Monday, March 16, 2009 7:50 PM
Subject: transmission rebuild

ok, at the risk of starting a fistfight, I am having my 4-speed 091
transaxle rebuilt. Any opinions on lubricant for this? I am not big on
synthetics because they are not "backward compatible".

This transaxle would not go into or stay in first gear. second gear holds
great but getting there is sometimes a little "iffy". no other known
problems, but what should I think about having done while the case is open
that a rebuilder may not neccessarily do without asking? Is replacing 4th
gear still an issue (popping out when worn)? special synch rings? anything
special?