Quote Originally Posted by JoFotoz View Post
It will give false speedo/mileage readings with larger/smaller tire diam/circumf...
.........but TOD etc will all still work as long as all 4 are matched.

And if you do change diffs... as some, including me have....

...you must change both
What I meant was, in theory you could run different sized tires on the back vs the front if the differential ratios were varied by the same amount, so that the RPM seen at the transfer case would still match. i.e. if putting larger tires on the back on, replace rear diff with one that has slightly more reduction.

However this wouldn't work in practice because;
a) it would be really hard to get exactly the right ratio and
b) I just remembered that TOD uses individual wheel speed sensors, not drive shaft sensors, so it would still see slip and constantly engage.

In theory you could fix (b) by hacking the wheel sensor electronics or magnet ring, but that's a crazy amount of effort just to have different tires.