Lorenz Gera Hobbing L5-150 retrofitted with Siemens PLC contol

I need help , my Lorenz gear hobbing machine retrofitted with Siemens PLC based control, The hob spindle and work table run with single motor, during cutting gear with module 2.5 both the hobbing spindle and table stops, after few seconds starts again, during this time motor does not trip due to overload. can any gear expert guide any mechanical check points electrically checked by siemens engineer no problem, unfortunately I do not have any manuals regarding mechanical assembly, also machine specifications .
can somebody help me and guide.