If there is a service manual for this accessory, please advise where I MIGHT GET ONE. iF NOT, i NEED TO FIND OUT HOW TO SERVICE THE GATES AT THE SIDE OF THE ramp. the crane carries the culverts thru the gates and releases them, but the gate closest to the building does not return completely, causing the culvert to twist and jam. Please advise as to how to remove the cover over the gate mechanism and how to adjust the gate travel.
Thank you!!