Gear roll over noise comes from the transmission itself. It is not a malfunction, it is a design compromise. It is the noise of the gears meshing as they turn inside the transmission. When designing the transmission, the noise can be eliminated or reduced by using finer teeth. The finer teeth are not as strong. So a given size transmission can be made stronger by using courser teeth but that also encourages noise. Of course a larger transmission could also be used, but it would be heavier.
Back in the days of the big block Corvettes, there was a transmission option known as the M-22. It was a stronger transmission ment for use behind mega power 427 cubic inch engines. It had the nick name of "rock crusher" because of the gear roll over noise that it generated.
Ligher flywheels seem to agrivate the noise. The noise tends to get worse as the clutch wears so it is usually less pronounced with a new clutch.
Our MTX-75 does indeed have some native gear roll over noise. It gets more noticable as the clutch wears. It tends to be a little more pronounced in the SVT, probably from the lighter flywheel. It doesn't hurt anything, it is just there.
