How many bottom rollers does a 20-ton excavator have?

Question

VANROCK Track Solutions · Accepted Answer

A 20-ton excavator typically has 7 to 9 bottom rollers per side, or 14 to 18 total. The exact count depends on the machine’s make, model, track frame length, and undercarriage design.

If you are checking a replacement part or planning maintenance, do not rely on tonnage alone. Two excavators in the 20-ton class can have different roller counts because of variations in carriage length, track pitch, and load distribution. The safest way to confirm the correct number is to check the serial number plate, parts manual, or the roller pattern on the existing undercarriage.

You may also notice the need for rollers before you count them: uneven track wear, a jerky ride, noise from the undercarriage, oil leaks around the roller seals, or rollers that spin poorly by hand are all signs that inspection is due. If one roller has failed, it is smart to inspect the whole side of the machine, because wear is often uneven across the track frame.

A few practical points can help avoid mistakes:
• Count both sides separately, since left and right undercarriages must match the machine design.
• Verify whether the machine uses standard bottom rollers, heavy-duty rollers, or a special carriage setup.
• Match parts by machine model and serial number, not just by ton class.
• Replace worn track hardware in a coordinated way when needed, so new rollers are not paired with severely worn chains or idlers.

VANROCK supplies bottom rollers and other undercarriage parts for 350+ machinery brands through an appointed dealer network. If you are working with an OEM brand such as Caterpillar, Komatsu, Hitachi, Volvo, or Hyundai, note that VANROCK is an independent manufacturer and is not affiliated with those OEMs.