How dirty could it be?

I clean a neighbors house whenever he ask me too; which is about very three weeks or so. Well, this time he asked if I would do a spring cleaning again. You know the routine, windows, baseboards, cabinets, carpet, that kind of stuff. Well, he is a single guy. Clean for a guy, but still a guy. So last week I got the bulk of the cleaning finished, except the carpet.

Well, today I go to clean the carpet. It seems that every time I take my steam cleaner to his house to clean the carpet, it stops working. Usually the belts that spin the brushes strip out. Well, upon taking the steam cleaner apart, I find that it is not the belt that is stripped, but the motor that spins the brushes. So now hubby will have to replace the brush spin motor for my cleaner because my ability stops at taking it apart to replace the belts.

So my question is, Is it possible for carpet to be so dirty that it will tear up a steam cleaner? I am finding that the answer to that question is yes. See, I have to clean my carpet about every five weeks or so, because whoever built this house, bought the carpet that was on clearance that week, so it is off white, no joke. Plus we do not wear shoes in the house. Therefore, my carpet does not have a chance to get just horribly dirty, just three kid dirty.