I would recomend removing the shaft and inspect the bearings on the brake caliper housing.
If its a double bearing like the 07's and up, they can easily trap moisyure between the bearings.
Mine came apart with moisture and after it sat overnight, the bearings rusted and seized up.
When I reassembled with new bearings, I packed the void between the bearings full of grease to eliminate moisture.
I tore it down this summer and the grease was still there, and no moisture!
Not to mention it came apart much easier.
The drive shaft can be rusted to the bearings and be a pita to remove, but good piece of mind to inspect the whole thing IMO.