GMC, timing chain replacement in Zevulun

GMC, timing chain replacement in Zevulun.
A timing chain must be replaced in the event of wear of this component, which is detected during a routine inspection. To change the timing chain, it is required to disassemble the engine: disconnect the battery, drain the antifreeze, remove the drive belts and heater hoses, remove the crankshaft pulley, fan and water pump, align the mark on the old timing chain and dismantle. Install a new chain. For that, align the marks, install a new oil seal instead of the old one, then carry out the above operations in the reverse order to disassemble the engine and check the operability of the new belt.