I have a garage door closing issue. door is about 40 yrs old but all parts appear is good shape. have an automatic door opener approx 8 yrs old. the door opens and closes very easilly manually. and opens ok with auto-door opener (which makes sense as its pulling) but on closing at half way point the door bounces or side steps left and right so appears to hop down... there was alot of side to side play in runners, adjusted inward, but does not appear to help... at a loss looking for ideas, suggestions... other than replacing all :-) could the door springs have an effect ... ?