JAckerman

1998 GS 300 Can anyone tell me what the "SNOW" function does to the transmission? I understand its purpose, but I don't understand what it does. For example, I know the POWER position changes the shift points.

Don't do it. You may pick up steering wheel vibration at 60 to 70 mph. Stick with the V rating.

Same problem. Only solution is to put on factory specified tires (probably V speed rated. Look on door column for correct size and rating. The fact that this started when you changed tires is even more of a give away that the cause is improper tires.

You probably have crud between the rotor and the axle hub. Take off and clean very thoroughly.

Battery, alternator, or ground problem. Make sure alternator can put out under load (headlights, blower, etc on)

Suggest you get original factory rims and recommended tires (probably V speed rated). Otherwise you risk the familar 60 mph shimmy.

Possibly the timing belt has jumped. Put strobe light on #1 cylinder and see if timing is way off.

Make sure there is no crud between the rotor and the axle hub. Clean very well with wire brush.

PUt the factory recommeded tires on it. Make sure you have the same speed rating as recommended (probably V rated)