The 60,000 mile service for my car is coming up, which includes replacement of the timing belt. My mechanic recommended to replace - apart from the timing belt - also the following as preventive: timing belt tensioner, idler pulley, camshaft seals, crankshaft seal and water pump. Total quoted cost for this (parts and labor) is $800. Does it make sense to replace all these other parts as well? The factory recommended maintenance for 60,000 miles does not mention this. Any advice greatly appreciated.