Tranny....
The pinion bearing is so bad that the pinion is moving and hitting the
differential carrier and locking it up till the thrust is reversed and the
pinion shaft get moved back into position...
Daryl of AA transaxle

  > 1984 Westfalia manual transmission
>
> Recently my Vanagon has started doing a weird thing. I'll start backing
> out
> of my driveway (or backing up anywhere) and as soon as I push in the
> clutch
> in the van will come to an immediate halt. Violently if I am backing up at
> a
> a faster pace. The engine does not stall or act like it will and if I keep
> the clutch engaged in all is fine, until I push it in.
> I replaced the clutch master and slave about a year ago and didn't have
> this
> problem then. Earlier this year I replaced the brakes but didn't notice
> any
> problems then either. I must admit though it feels like the brakes are
> grabbing the rear wheels but it only does this if I am coasting after
> having
> been in reverse. Coasting in a foreword direction is fine, leading me to
> believe the brakes are not the culprit.
>
> Could this be a sign that my tranny is going bad?
>
> --
> Brien K Dews CC-AWCI
> www.busesbythebeach.com
> 84 Wolfsburg Westfalia
> 89 Vanagon 'Bluestar'
> 74 Westfalia
>