Dan wrote:

I'm going to take a 3 week road trip in September.  My '85 is running
well, and I'm confident it will stay that way.

The only item I'm concerned with is the infamous 3-4th gear failure.  My
Westfalia just flipped 140,000 miles - from what I read, this is the
spot on the odometer when the transmission is most likely to fail.

1) Should I get a new one now, or wait for this one to bust? I plan to
keep the van for few more years.

2) What's an easy way to see if the trans has been replaced before?  I
bought the van without any records of service.  I did have it out to
replace the clutch last fall, but didn't notice any signs of work. (but
I wasn't really looking)

Dan,

If you haven't already done so, it may be worth the trouble before your
trip to drain your gearbox and refill with synthetic transmission fluid
and a bottle of nulon transmission additive(or equivalent).

Seems to extend their life from my experience and observations, and
without service records to check, it's prolly better to assume the
transmission has not had a fluid change in some time....er, unless you
did this when the clutch was changed?

Otherwise, enjoy your trip. Transmissions usually give you some advance
notice when they are no longer happy. 

Cheers,
Steve O
NSW Australia
'92 Transporter WBX Kombi
'00 Transporter Double Cab
'03 Transporter Double Cab (work truck)
'78 Landrover Series 3 Soft top (ex-Aust.Army)