Well, I took the 89 Westy on its first long-distance outing - round trip
of about 1200 miles from New Orleans for some whitewater kayaking in the
NC Smokies and East Tennessee on the Nantahala and Ocoee rivers.
    On the way up I-59, about halfway through Alabama, the transmission
slipped out of 4th gear to neutral.  Then about a half hour later, it
did it twice in 5 minutes.  Pulled over to a gas station and looked
under to see if it looked like it had sprung a gear oil leak or
something obviuos on the shift linkage.  Nothing visible.  When in gear,
it sounded normal.  So I kept going.  It happened about every 2 hours,
usually twice in a few minutes.  Did not seem to be related to any
specific range of speed or RPM (other than I was always somewhere
between 65 and upper 75 since I was on the interstate).
    It didn't happen when on local highways though - on the winding
roads, I rarely went over 55 or so.  On the way back, it happened some
more.  Got home with no serious trouble this morning.
    I figured it was more likely a linkage problem than internal, though
I could be wrong.  I decided to risk doing internal damage since I do
have a spare on the 87 bus I picked up cheap.
    So I wonder if anyone has any idea what might cause this ?  A month
ago, I had a dealer work on the linkage (shifter bushing and some seals
- I've got part numbers at work and can post them later if it's
useful).  So it could be a warranty situation.  On the other hand, I've
read about the defective design on the part for shifting between 3rd and
4th, but I figure that would more likely disable the vehicle than do
this, right ?

Any ideas will be appreciated,

Dave L.
89 Westy  "Desire"
87 Bus