Cottrell adds Technical Bulletin In an effort to simplify procedures on greasing the bearing housing on the tandem slider deck (Lower #6) screw assembly, Cottrell has created a technical bulletin to aid our customers and maintenance facilities. Depending on the use of this position, this procedure could be required between 10 – 14 months of use. You can also find this bulletin in our Operator’s Manual section of the website. This is where all Service and technical bulletins will be posted. If you have any questions, please contact a Cottrell representative today.