Why have timing belts?

Most older cars with timing belts have overhead camshafts. That means there's quite a long distance between the crankshaft and camshafts. Without chain idler take-up slides or idler pulleys the chain will whip around a ton. That means sloppy cam timing.

Toyota's have dropped all timing belts 6 years ago in favor of timing chains for the very reasons you bring up. Ford V-6 motors with dual overhead camshafts have chains also. Nowadays new cars with with variable cam timing systems timing chains are a must. So what if they need lubrication. They out last a cheap timing belt and cheaper aluminum pulleys three or four to one. Quietness baloney! You could walk buy 100 cars with the engines running and I'd defy anybody to pick out a motor that made more noise with a chain.

In the beginning when cars were rear wheel drive it wasn't a problem dropping the water-pump to remove a timing belt. Now with front wheel drive cars and cross mounted engines everything is pinched into a small space and it's labor intensive to remove pulleys, water-pumps covers and shields just to get to the timing belt. Originally a complete timing belt system was less expensive to manufacture.

Last time I put a timing belt on a VW, the part was $30 and it took me about an hour.

If the chain tensioner had gone bad on a car with a chain, it would have taken over 3 time as long, and cost more.

The problem is that with a lot of transverse mounts, they have not designed the belt cover very well and it is harder to do than it should be.

And on interference fit engines, they should put an extra wide belt, or larger diameter sprockets.

Less expensive to manufacture, doesn't have to be encased and lubricated and can do multiple functions such as driving the water pump.

HOWEVER, I totally agree with you - it's absolutely ridiculous to put a timing belt on a non-interference engine or on a vehicle that takes 4 -6 hours to replace it.

The manufacturer is building the engine the cheapest (for them) way possible and the belt is slightly quieter than a chain. They could care less that you have to put out big bucks, down the road, to replace it. If you check it out you'll find that American cars have almost always used chains. It's the, so called, "customer oriented" foreign cars that prefer to use a belt.

Why are good answers getting thumbs down? I cant see one bad answer above??? bye see you all next year

My answer is COST! chains are expensive

its like saying why are so many cars front wheel drive? 2 answers 1 it's cheaper and 2 its more efficient

Well, you know what's going on with Toyota right now.

Timing belts are more quiet, do not require lubrication, more efficient, and most importantly, they resist stretching.

Lower production costs.

Less weight.

More design flexibility.

Chains also can and do fail!