I work in industrial maintenance not a forklift mechanic so I need some help. One of our forktrucks keeps over extending the side shift to the left. I took the carriage off recentered the cylinder and grease the carriage. There is a v shaped aluminum channel that it slides on. I saw metal shavings and could tell it hasn't been greased so I figured a heavy bundle and side shift caused too much friction. Recentered put everything back now it's done it again a week later. I didn't see any stops to keep it from over shifting.