aux hydraulics Backhoe threads are for the tractor/ backhoe section. You don't say what backhoe you have. Check to see there is no extra spools on the hydraulic control bank that are unused, if not you might need to add an extra spool or other options depending on what the existing hydraulic set up is. No welding necessary if you use a thumb like this.
Discuss this in the forum topic Adding auxilary hydraulics.