Wear on the bottom rollers and top rollers

How do I know if the bottom rollers on my excavator or mini-excavator are worn out? There are several reasons to replace an undercarriage track roller or top roller. Here, we list some reasons that might prompt an undercarriage overhaul:

Leakage from bottom or top rollers

If you notice a greasy deposit around a roller's shaft, there is a good chance the roller is leaking oil—whether rapidly or very gradually. This indicates that the internal seals have failed. It is usually only a matter of days before the roller runs dry and subsequently breaks down.

Damaged bottom roller / top roller

Once a bottom roller loses its oil, its internal lubrication is lost. Consequently, internal steel components (shaft and roller) rub and grind against each other, eventually causing the internal mechanism to wear away almost completely. The roller is then ruined and, due to excessive play, rattles against the chain. Replacing the roller is urgently necessary, as further wear could cause parts of the roller to break off and damage components such as the track guards.

slijtage aan de onderrollen en bovenrollen waarbij de rol los op zijn as zit.

Worn tread surface

When referring to wear on bottom and top rollers, the term usually applies to the roller's tread: the running surface that makes contact with the track chain. A heavily worn roller exhibits a tread that has taken on a concave, trough-like shape.

een nieuwe rol van het rijwerk die geen slijtage vertoont.

Slijtage aan de onderrollen en bovenrollen waarbij de het loopvlak vervormd is.

However, a roller showing a cupped tread pattern is not necessarily 100% worn out. The key question is: how deep is the wear?

The depth of wear at which a roller is considered 100% worn out depends on its diameter. As a general rule of thumb, rollers in the 13-ton to 40-ton class have a hardened layer of approximately 5 to 7 mm deep. In other words, if you measure a worn roller and find its diameter is 10 mm to 14 mm smaller than the original size, it can be considered nearly 100% worn out. For the bottom and top rollers of mini-excavators, this hardened layer is only about 3 mm deep.

Questions?

If you have any further questions regarding wear on the undercarriage bottom rollers and top rollers, please contact us today at +3292510796, via [email protected], or through the contact page.

Click the following links if you would like to know more about:

Wear on undercarriage sprockets.
Wear on the undercarriage chain.
Wear on excavator track shoes.
Wear on undercarriage front idlers.
Wear on track guides.