In 2017 the Elizabeth Tower (aka Big Ben) is going to undergo a three year renovation programme This includes the clock face I get the impression that even if the clock is working Big Ben may be silent The web site is not very clear www.parliament.uk
The bells will be silent for a few months I seem to recall from an interview. The tower needs maintenance and while they do that they can overhaul the Great Clock., I believe they will be changing some of the glass in the dails too, I heard they were trying to source a match. The Palace of Westminster is about to undergo a massive restoration and maintenance programme costing billions.
I have just found a website containing a lot of general facts about Big Ben I hope it works outside the UK http://www.bigbenfacts.co.uk/facts/