This is truning out to be a "Mike" thread
Mike in Az, the issue I saw was not wear, it was a rock or dirt as well. I'm sure your version has a better shield than the OEM foam pad and thus much less likely for the dirt issue. I know it's a lot more robust mechanically and electronically. Wow, a 1% fail/wear rate over 6 years is pretty good, wish GM worked with you earlier
Mike in Atl, just noticed that you mentioned the R has been down for a month?

Might was well just order a new Mike in AZ fan, it should be to you in 2-3 days, get that thing back on the road!
Mike in Ga