Undercarriages are designed so that the Bottom Rollers bear the weight of the machine, while Top (Carrier) Rollers (where fitted) guide the track over the frame. Worn rollers should be replaced to prevent damage to other undercarriage and drive components.
For tensioning and guiding the track around the front of the undercarriage frame. Worn or seized idlers will create drag and can result in severe damage to tracks and undercarriage due to frequent de-tracking.
Available for most popular mini & mid size excavators from 0.75 to 7 tonnes, most are bolt on type. Vital for good track life, these should normally be replaced when fitting new rubber tracks.