Very true, i have seen a similar effect with 4wd buggies having larger wheels on the back and smaller at the front one diff will where out sooner than the other if not both, there a a huge array of 1/10 scale models try searching diffs and analysing what yours looks like compared to the others. It is a shame they put 1/10 diffs in a 1/8th but that would of been manufacturers decision to meet the price point.