Timing chains are built to last the lifetime of the car. There are two main differences between a timing belt and a timing chain. For starters, a timing belt is made of rubber, whereas a timing belt is a metal chain. But more significantly, a timing chain is meant to last the lifetime of the car. On the other hand, V-belts must be regularly adjusted to maintain functioning properly. Furthermore, serpentine belts can last much longer than v-belts due to their increased flexibility and ability to stay tensioned. For that reason, serpentine belts need to be replaced every 50,000 miles, while a V-belt must be replaced every 30,000 miles. Tech Tip #1: Belt Inspection Changes. With traditional Chloroprene (neoprene) serpentine belts, standard diagnostics called for replacement of the belt if it showed three cracks in a three inch section. However, today’s EPDM belts are much more resistant to cracking, since they can run up to 100,000 miles or beyond without visual cracks Timing belt advantages: Cheaper to manufacture and quieter. Timing belt disadvantages: Requires periodic replacement and can fail without warning. Timing chain advantages: Durable and tends to becoming noisy before catastrophic failure occurs. Timing chain disadvantages: More costly to manufacture and can be noisier. From 2010 to 2023 all Toyota 4Runner models have a timing chain and an interference engine. From 2003 to 2009 the 4.0L 4Runner models have timing chains and interference engines while the 4.7L has a timing belt and interference engine. From 1984 to 2002 all 4 cylinder 4Runners have timing chains and interference engines while the V6 models have Timing belts are used on OHC engines because the head and the block can't be sealed across, thus the chain housing would leak oil. Chains are used on pushrod engines where the crank and the cam are both in the block, so the cover doesn't cross a split line. Belts of course don't need oil. Historically anyway. .

timing belt vs v belt