Do not forget to re-seal the gearbox with RTV soon after you’ve got discovered the appropriate mix. Even though they are referred to as “gaskets”, they will not seal your gearbox on their personal.
If almost everything seems standard, try changing the equipment-mesh. This is completed with the mylar “gaskets” that sit in between the major gearbox situation and the enter/output caps. Consider including or taking away some of these spacers till your gears have around 1/eight”-one/four” of free enjoy. Experts can get replacements ($1-2) in varying thicknesses, but we advise the rapid and filthy technique of reducing your very own out of 
a sh
eet of mylar.
“Groaning”, “creaking”, or “popping” all audio type-of comparable in excess of-the-phone. The best issue to do is to disassemble your gearbox and take a seem at the gears and bearings. The problem will generally current itself in the way of damaged/missing equipment tooth, toasted gears (like that photo on our house webpage), or blown bearings.
My Gearbox is Groaning/Creaking: