To be honest I do not own this lens nor do I own any SDM lens but I have noticed discussions
from other forums concerning SDM failures with the Pentax SDM lenses that there could be a
higher than normal failure rate and some have even went as far to have an active petition to
Pentax to this and respond.Many,like myself are patiently waiting for SDM ll to be released.Many
have sited no problems at all so argument continues but surely something is happening,maybe
QC.Whatever the reason there does seem like a problem could exist and worth exploring as SDM
should be more quiet than the screw drive lenses I have from all reports and reviews I have
read,Regardless of the reason only Erik can make this decision.if it was me it would go in for
service at the first sign of a problem SDM and hope Pentax will be kind knowing they could have a
problem....just my 2 cents.....
Larry
Likely they won't charge you for it. It may just need a cleanng.
Asher