Yeah... the ZD uses a Sprag Clutch in the Pulley which can be problematic.
Some people stick with a Clutch, some change out for a solid pulley
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Yeah, i decided to stick with the clutch after looking around a bit, reading and asking a few opinions.
The original lasted 185k kms, Id be happy to get the same out of the replacement.
When I replaced mine I went with a 110 amp with solid pulley, no problems after 18 months.