Mark said:

Date:    Fri, 11 Jun 2004 18:46:51 -0700
From:    mark drillock <drillock@EARTHLINK.NET>
Subject: Re: Syncro tranny problem

This is a very common error. You likely attached the linkage wrong at
the tranny. The plate that bolts to the ears on the tranny can be bolted
to the wrong side of the ears quite easily. When you do it wrong there
is not enough travel available to bet all of the gears to engage. With
the shifter in neutral, look at the rub/wear area on the shift rod at
the tranny bushing. You should see an equal amount of wear/rubbing marks
on both side of the bushing. If not, take the 2 bolts out and move the
plate to the other side of the ears.
~~~
I will add one more note to the wisdom above.  Make sure that there is
enough "float" in
the shift linkage.  As the van accelerates and decelerates the transmission
moves forward
and aft.  If there is insufficient float, second and fourth gears can run
only partially engaged
and will wear out very quickly.  A transmission R&R done at a shop not to be
named forgot to
check this all important item on a transmission that I had just had rebuilt.
Fourth gear failed
after 1600 miles and began to "pop" out of gear under acceleration.  Cost me
another rebuild and
the shop refused any help in the matter claiming the shift linkage is "not
adjustable".  Not so
of course.

Anyway inquire of a good rebuilder how to determine this float.  The defect
occurs when the plate
to which mark refers pushes against the shift rod slightly enough to
partially disengage the gear under load.

I highly recommend as I have done in the past, Jeff Field at Transaxle
Engineering in Chatsworth for
consultation and repair.  He did both rebuilds for me and the second one is
doing just fine after
a bazillion miles with a properly adjusted linkage.