The weakest point of a JK front axle be it a D30 or even Rubicon D44 is the size and strength of the axle tubes.
Many people aren't aware but the D30 and D44 front axles are the exact same tube diameter and strength - they can bend easily with mild and or extreme wheeling which causes the internals to fail due to misalignment of the internal components. If you're planning a trip over some rough terrain or seem to "get air" under the front axle when offroading, then have a think about getting some sleeves knocked in before your next trip - you're wallet will thank you later.
Designed to increase the strength of the Front D30/44 Axle housing that is prone to bending when larger off road tires are used and
When having this product installed, consider having your JK's ball joints replaced with some HD Synergy Greasable Ball Joints as the whole front end is pulled down to install these sleeves. This saves you money and downtime in the long run, as the sock ball joints don't like taking the big off-road hits.
- knock in design (welding optional but not neccessary)
- increased wall thickness reduces failures due to axle tube flex
- Larger Rubicon factory 30 spline axles still fit with these sleeves