You can replace the threaded end by cutting of the old threads flush with the splined part then drill out the centre for a 6mm tap, tap and insert a 6mm bolt long enough to be able to cut off the head and have back the original length of threaded stud left.  The splined part is as other have said, probably just full of soft metal from the wiper arm. clean the splines with a small sharp pick, install a new or good used wiper arm and you should be OK.  When you tighten down on the new nut and WASHER, make sure the WASHER has an inside diameter that will fit OVER the first mm or so of the splined end of the shaft and that the outside diameter of the WASHER will allow space for the plastic cap to be inserted.  That WASHER that was in there is a very odd, special washer !

On 2011-09-20, at 12:00 AM, Automatic digest processor wrote:

> And the threaded end, can you add another washer below the nut to move =
> the nut away from stripped section? And try a new nut.

Cheers,    

Frank Condelli
Almonte, Ontario, Canada
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