You will need to take out the whole element and send if for a complete overhaul – which includes repairing of the screw profiles, changing the bearings, etc, etc.
2600 hours is very little running hours for a screw element in a stationary compressor – usually they last for about 40.000 running hours.
The most common causes are:
- running in reverse direction – it will usually last only a few minutes
- severe overheating – usually due to blocked oil channels
Sorry I can’t be of much more help here.