A logistics company reported that a Toyota 8FD25 forklift's forks tilted to the left when raised above 4 meters. This made it dangerous to place pallets on high racks, as the load could slide off.
The technician inspected the "Lift Chains." The chains are anchored to the cylinder carriage. He measured the tension using a chain tension gauge. The left chain was 40% looser than the right chain. He tried to adjust the anchor bolt, but the threads were stripped. The stripped threads allowed the left anchor to slip under load.
He then examined the "Lift Cylinder Rods." He found the left cylinder rod had a slight bend near the middle. The bend was likely caused by a previous impact where the fork carriage hit a rack cross-beam. The bent rod created friction in the cylinder gland, causing the rod to extend slower than the right side. This "differential lift" pulled the chains out of alignment, twisting the carriage frame.
The repair involved replacing the left lift cylinder (the rod was too damaged to straighten). He also replaced the chain anchor block with a reinforced steel block and re-tensioned the chains to match. He tested the lift function: the forks rose perfectly level. He also checked the "Carriage Roller Bearings" for wear due to the twisting force and replaced two worn rollers.
