You need to use MT-90 not MTL
Direct quote from the Redline website
"MTL is a low 70W at very low temperatures and a high 80W, nearly an 85W, at elevated temperatures, providing adequate viscosity to prevent wear and deaden gear noise. MT-90 is a thicker 75W90 version of MTL."
You need to use mt90
tC's use 75w90
75w90=MT90
70w80=MTL
Direct quote from the Redline website
"MTL is a low 70W at very low temperatures and a high 80W, nearly an 85W, at elevated temperatures, providing adequate viscosity to prevent wear and deaden gear noise. MT-90 is a thicker 75W90 version of MTL."
You need to use mt90
tC's use 75w90
75w90=MT90
70w80=MTL