A friend's BMW 2002 years ago had that problem.  He stopped for gas and on restart had no go.  Turned out to be a rear CV had given out. 
Stephen 

    On Friday, October 27, 2017 9:21 PM, Dennis Haynes <d23haynes57@HOTMAIL.COM> wrote:
 

 Of the fast with no warning failures the usual suspects are the CV joints or an axle, the clutch disc center hub, and the input to main shaft coupling. Since you are getting knocking I would look at the CV joints/axles first. 

Dennis

-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of David Bohannan
Sent: Friday, October 27, 2017 5:00 PM
To: vanagon@GERRY.VANAGON.COM
Subject: Shift but no go

So it sounded like something “let go” power then nada and got a bit of a knocking noise when trying to get into gear.... anyone? Clutch feels fine- shift feels firm- but did a shaft break in there or something?!? Help!

Dave
85 manual schtuck