On T-GAUGE SD Diesel Locomotives. I believe that one could have the rear axle not powered like MINITRIX did with their GE U28C and GE U30CG Locomotives in order to represent a 6 axle Locomotive. Yes, I say. Take a page from MINITRIX. Tom
That's how my SD70ACe trucks are built. The way the T mechanisms are currently designed, there's no way to physically gear the third axle.