The present disclosure provides a track-type work machine including a vertical idler adjuster, a track-type work machine including a roller frame and an idler mounted proximate an end of the roller frame. The upper member is loaded with upper contacts with contacting portions arranged on an upper surface of the mating portion and a shielding plate is located between the upper and lower surface of the upper member. A second rotary shaft of the second roller is rotatably supported by the first housing in a state of being positionally movable.