If so, how have they been?? It sounds like a lot of people have the 2/3/4 shackles and use the 3" hole. Anyone have success with the 4"???

 

Success in what sense?

 

Most with the 2/3/4 use the 4"... That's the point of getting the 4" shackel.

I have it on my '04 and the rear is about a 1/2" higher than the front.

 

No vibration or poor handling. In searching here and NLOC I kept reading those results.

I plan on trying the 4" myself, but was just wondering.

 

If you're expecting a 4" drop with 4" shackles you ain't gonna get it. You'll most likely 3" at most

 

I used the 4" setting. No problems. Gave about a 2.5" drop.

 

Vibration would come from driveline misalignment, which may or may not happen irrespective of which lowering method is used.

"Poor handling" is a bit trickier. There are many who claim that longer shackles increase the slop in the rear end because the suspension now has another possible movement point. I have never seen any reliable data confirming this. It seems to be a matter of logic, rather than real information.

Martin (I'dwin) is running CE traction bars on a lowered Lightning. There is not enough room to slip a credit card between the axle mounts and the frame rails. Yet his have not rubbed, which strongly suggests that his axle is not moving sideways under cornering. Maybe he doesn't corner hard enough, or maybe the axle movement theory is overblown.

If we are going to get theoretical, the best way to lower the rear is with hangars rather than shackles. According to the textbooks, the best handling is achieved when the leaf springs are flat. Ours are decidedly tilted up in the rear. Using shackles increases the spring angle, while using hangars flattens the spring angle.

Shackles are so cheap that I recommend installing them and seeing what you think. You can always sell them used if they don't work out for you.

 

Dr. Skelton knows what he is talking about!