Since August 2025, there has been a new mounting concept for the BDU31YY (narrow variant, or wide variant including adaptor), BDU34YY and BDU38YY drive units.

The frame sleeves used so far are being replaced by frame bushings. The frame bushings and associated bolts are backwards compatible with the drive units that were still installed with frame sleeves. The adaptor remains unchanged.

Choose correct fitting according with the product picture.