Will not neglect to re-seal the gearbox with RTV soon after you’ve got identified the right mix. Even even though they’re referred to as “gaskets”, they is not going to seal your gearbox on their very own.
If every thing looks normal, attempt altering the equipment-mesh. This is carried out with the mylar “gaskets” that sit between the primary gearbox circumstance and the enter/output caps. Try including or taking away some of these spacers till your gears have approximately one/8″-one/4″ of free play. Professionals can buy replacements ($one-two) in various thicknesses, but we advise the rapid and dirty method of cutting your possess out of a sheet of mylar.
“Groaning”, “creaking”, or “popping” all sound kind-of related in excess of-the-cellphone. The greatest issue to do is to disassemble your gearbox and consider a seem at the gears and bearings. The problem will normally present by itself in the way of broken/missing gear tooth, toasted gears (like that photograph on our property web page), or blown bearings.
My Gearbox is Groaning/Creaking:
Fortunate for you, we did 
a compose-up on our blog. It really is referred to as “How to change the input shaft on your rotary cutter gearbox”.
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