Complete overhaul of gear unit

The Eisenbeiss gear unit was in continuous operation without problems from 2001 until 2012 in a PVC pipe extruder. During s period of scheduled downtime, Eisenbeiss Industrial Gear Service were contracted to overhaul the gear unit as a preventative measure. When the gear unit was dismantled, considerable damage was discovered. The operational reliability of the extruder was already at risk and it was high time that the gear unit was repaired.

The damage indicated that it had been operated with an elevated oil temperature, possibly due to problems in the lubrication circuit. When the gear unit was started up again, the original problem came to light: one of the lubrication lines had been connected up incorrectly.

Application: PVC pipe extrusion
Gear manufacturer: Eisenbeiss
Type: ZGD107.5 HD-A
Gear type: counter-rotating twin screw extruder gear unit
Data for repair: drawings and parts list available


  • Inside the gear unit the gears were clogged with carbon deposits (indicating that the lubricant had been overheating)
  • Severe damage to the bearings and gear teeth
  • Bore in the casing were worn due to the outer bearing race rotating
  • Crack in casing plate

Work carried out:

  • Dismantle and inspect all gear unit components
  • Make all gear teeth parts new
  • Make new casing plate
  • Recut casing bores and make bushes
  • Purchase and replace all bearings and seals
  • Installation, test run and painting
Getriebe Reparatur

Gear condition before and after repair

Getriebe Reparatur

Tooth breakage in low ratio gear unit

Getriebe Reparatur

Distribution gear heavily clogged with carbon residues

Getriebe Reparatur

Distribution gear with new gear components

Getriebe Reparatur

Installation of overhauled extruder gear unit