New tires affect on the TOD system

I still have my original stock tires (18" Bridgestone Dueler HT) on my VX and the front tires need replaced. My question to everyone is if I only replace the two front tires with this affect my TOD system? Should I replace only two or do I have to replace all four? Any feed back will be greatly appreciated. :cool:

I believe I recall that the TOD does not like more than 1/4" difference in diameter.

I would not recommend replacing just two, unless you install a TOD switch and manual hubs. Then life with a VX is just easier. :)

-Daver