1999 Venture extended van - Thursday the van started to lunge every
time the transaxle would shift.  There is also a whirring sound coming
from below the vehicle while the van is moving between gears.  I drove
it about 2 miles once it started and parked it in my garage and left it
there since.  The fluid looks red, clear, full and clean.  There is no
obvious odor to the fluid.  I have approximately 59,000 miles on the
van.  There is a history of a cracked exhaust manifold gasket which was
replaced around 40,000 miles.  No other major repairs.  The outside
temperature was about 95 degrees and the van was operating at the
normal temperature.  Does this sound like a new trans is likely or
could there be some components that should be checked before a trans is
suggested?  What should I expect from my mechanic?  Are there any trans
problems known concerning GM minivans?