Retracking is when they take either the top three layers of wood(and sometimes all of the track) off and replace the wood. Rebuilding they replace a section(or whole) of the structure, all the way to the footings. Problem is, even with rebuilding the supports that when wood is like a hand rail on a porch, the wood will at some point, start to sag.
Notice the sagging handrails. Imagine riding over those, wooden coaster track will not sag that bad, but when are going over even a small bump at high speed, you are going to feel it. Last time I rode Thunder Road, the sag was so bad in the turn before the lift that you could see and feel the cars going over them. The shake you that causes the roughness on Hurler is from the sag.
Turn 1 is the turn after the station, but before the lift.
Turn 2 is the curving drop from the lift to the top of the small hill prior to the main drop.
Turn 3 is more commonly refered to as Turn 1, and is the turn at the bottom of the first drop.
Turn 5 is the fancurve under Turn 2.
