Well, you can always drop in CSC & ask for a check up. You may not know if there is any thing wrong with it.
The tech will check through your cam, usually they will recommend a cleaning. Which usually will involve cleaning of the mirror box area, the reflex mirror, focus screen & sensor.
If they detect other minor faults such minor focusing issues they will recommend a focus adjustment & calibration as well.
Usually they will also upgrade the firmware if its applicable.
They will go through the same check & recommendation routine with the lens.