Undercarriage

Idlers

Front and rear idlers that guide the chain onto the rollers and pass shock into the recoil assembly. Supplied as complete units or as shells for rebuild.

Features

  • Idler tread and flange wear changes chain alignment, so a worn idler shortens the life of every roller behind it.
  • Idlers are rebuildable: the shell can be re-treaded by welding and machining where bore and shaft remain within tolerance.
  • Tread profile is matched to chain link width; a narrow tread under wide links causes edge loading and rail wear.
  • Idler yoke, shaft and bearing condition is checked whenever the idler itself is replaced.
  • Rear idlers on some dozer frames carry drive load and use a different hardness specification from front idlers.

Specifications

Figure Typical range Unit Why it matters
Position front / rear Different profile and hardness.
Outside diameter (new) 430 - 760 mm Wear reference and chain geometry.
Tread width 60 - 130 mm Must suit chain link width.
Supply form complete unit / shell only Decides whether shaft and bearings are reused.