I have an oldie but goodie and now have a problem that is really throwing me off. The longer chain on the left side that moves it fwd/ aft is binding and pops off. Does anyone have any ideals what could be causing this. Is it the hydraulic motor on that side but the smaller chain is fine. The axle looks to be in fine shape and there is no teeth missing on the gears? Please any info or thoughts that could help me. I have mechanical ablities worked on jets for years but this little bugger just is getting my goat. Thanks ahead of time.