There are no bushings.  The shaft rides directly in the aluminium housing.  "Usually" the wear is not so bad and there are seals at both ends that will take care of any leakage.  The throttle plate sticks because it catches in the groove in the bottom of the throat of the throttle body made by where the butterfly plate has been rubbing all its life.  Bad design !
I fix this with a shim.  <http://www.frankcondelli.com/staging1/store/index.php?route=product/product&path=61_125&product_id=1003>

On 2013-08-15, at 12:33 PM, Automatic digest processor <LISTSERV@GERRY.VANAGON.COM> wrote:

> Don't the bushings just wear out after
> some point?

Cheers,    

Frank Condelli
Almonte, Ontario, Canada
'87 VW Westy, '00 Kawasaki 250 Sherpa, "98 Ducati 750 Monster & Lionel Trains (Collection for sale)
Frank Condelli & Associates - Vanagon/Vanagon Westfalia Service in the Ottawa Valley
BusFusion a VW Camper camping event, Almonte, ON, June 06 ~ 09, 2013