Sorry for this being so late but I have been behind on school work lately.  I
had this happen to me last summer....boy does it suck!!!!  I had a knew clutch
put in and t/o bearing put in so I know it wasnt due to rust or anything like
that.  I also had replaced all my tranny/differential fluid with redline
MTL....so Im just at a loss to why this is happening at the time it happened.
I thought maybe the van was too hot...it was my second day out on my trip
through our country and had traveled about 500miles that day so far and when
we exited off the highway outside of Cleaveland Ohio I couldnt get out of 3rd
gear.  AT least you were on a down hill...I was on the up hill....somehow I
got through the light and into the gas station rideing the clutch to hell and
haveing all the traffic beeping at me!!  So I looked under the van and
nothing..not a sign of anyting wrong....then I let her sit for awhile and kept
pushing on the shifter....and then started her again and pulled on the shifter
with the clutch pushed in.....some how it popped out...I could then go into
second and reverse with major trouble but it went it...so we left the gas
station to see if anything else would happen.....WELL IT DEFINITALLY
DID.......there was this lovely loud snap ...than kinda bang....and the van
shifted smoothly ever after!!!!!!!!!!!!!! Somehow she fixed herself and now
its been 24k since then.  From what other listee's have said I think that it
was syncronizer that went, I just hope that doesnt happen again.  I also think
that if it wasnt that then it is the bushing that need to be replaced(which I
plan to do sometime in the near future).  Well hope that helps you and if you
need anyother info email me.

Tim G
87 gl syncro(164k)