Ну что, Nitro отписалось. Ниже письмо в оригинале.
38.5” tires on a toyota 8”? While the Nitro gears are the strongest and best quality gears you can get for toyota, It is unreasonable to believe that any 8” ring & pinion could hold up to 38.5” tires.
It is very unlikely that there was defect in the gearset. Proper heat treating is evident in the photo. I realize this does not tell all, so You can submit an RGA form here, gut the unlikelyhood of a defect will likely not warrant your shipping cost to return the part for warranty consideration.
I would suggest upgrading the front diff to a larger setup. We are actually doing this on our BJ73 project by going to a custom 9.5” axle housing and utilizing the 80 series type knuckles with chromoly cv joints etc. We will only be running 37’s
Они признают, что пары 5.29 для колес 37 дюймов

Смеяться или плакать, пока не знаю. Вечером отпишу им, что про размер колес на их сайте ни чего нет. Задам вопрос какие случаи признаются у них гарантийными.