Question,

Are Radial Bearings Necessary for coilovers? Or are they for true McPherson strut type of suspension systems?

I understand they are offered as an upgrade, but are they beneficial for the G37 type of suspension or are they really for McP struts?

 

Nevermind, I just found this:

Annoying spring binding noises that sound like a "thunk" or a "twang" are a common problem for full-coilover systems on strut-based vehicles (applications that have camber plates.) This is an issue in all race coilover applications regardless of the manufacturer. These noises are a result of the mechanics of strut-based vehicles because the whole shock assembly turns with the wheel. On OEM setups there is a built-in bearing on the top hat assembly that isolates the top hat from the rest of the strut assembly. On race spec'd coilovers the spherical bearing (pillow ball hat) is not designed to handle the load. Since the spherical bearing is not designed to deal with these forces, the spring is forced to turn with the assembly and drags on the spring perches. The spring dragging on the perch does not damage the coilover assembly, but on a daily driver this "thunk" or "twang" noise can get old.

 

The Gs don't run the camber plate configuration.

 

Coil springs can indeed rotate as they are compressed and extended. It's not much, though. Still, most independent OEM installations provide an indexing dent in either or both mounts of the spring. Coil-overs can get by without bearings. And calling the front damper of our G a strut is incorrect. It's a coil-over-damper assembly. Non-adjustable, but still a coil-over.

MacPherson strut suspensions are also technically coil-over-damper assemblies. However, they use the upper mount as a suspension locating point, unlike the G. The steering gear rotates the entire strut so it needs a Torrington bearing up there to prevent stiction.