The gears were easy to replace. I had no adjustment to make. I didn't even remove the extruder motor. I removed the hobbed bolt and fitted it to the new large gear and transferred the locknut to the small one, assembled and away it went. The new gears printed so cleanly I had no clean-up to do at all. I gave them a little bit of PTFE spary and they meshed perfectly, smooth and quiet.
The 'reprint' test, shown in the short video clip is the exact same gcode file that was used to print the piece shown in the previous post. By running the same gcode it allowed me to do a direct comparison of the difference the new herringbone gears made. This version has a fuller body to the tenderals and less stringing. I'm very pleased with the result of the change. I can now fine-tune my retract settings with more confidence!
Thanks for viewing!