Quote Originally Posted by 55 Rescue Dog View Post
What is the big benefit of a narrow axel over a wide axel, especially on an IRS? Seems backwards to me. Something to consider, with your single shear dog-bone mounts, it would be a great application in which to use spherical bearings on., which would eliminate the twisting forces. A little noise is just part of the mechanical symphony.

This is exactly what I was inquiring about but c-nut discounts that. You (55 Rescue Dog) seems to understand my concern. “More directions” as in arc travel not linear straight line. The smaller the arc radius the more inward and outward displacement. I just see a lot more than 2” spindle movement up and down suspension travel on an arc path centered on the inner u joints. Spirited driving will see a lot more. So I don’t buy 2” travel. Pot holes are more not to say inclines and bumps.

The purpose of a 4 link is to control the up down movement so it is more linear rather than arc. True this is more of a concern with a sprung differential. Thus the position of the pivot and link length will have optimum functional positions and lengths. This is what is implied by “tuning” regardless if a fixed or sprung differential.