The D30 in the YJ is strong enough to handle 35s but the weak point will be the u-joints unless you have the larger 297 joints. As for reliability, larger tires cause all the front end parts to wear faster especially the bearings and ball joints. Right now I am running 33x12.5s on my YJ and I have had the same unit bearings for about 3-4 years now and I drive it a fair bit. However, when I had my 31s, I went through a few sets. Unit bearing life is a balance of tire size and wheel offset