I was wondering if anyone would have any idea why I would have stacked shackles in the rear end of my truck. The truck is a 1997 f350 cclb.

The arrangement is rear hanger one shackle then another shackle then the spring.

 

 

A picture is worth a thousand words.

 

i didnt notice it till i uploaded this picture but i think it answered my question....they appear to be a setup called velvet ride. its supposed to make for a better ride unloaded...so now off to find replacements...

 

They went out of business and cant find a web link
https://www.superdutydiesel.com/thre...hackles.10325/

 

Sulastic Rubber Springs. Sulastic

 

Hinged shackles were a trendy thing back in the late nineties or so, IIRC. There were lots of articles in 4x4 magazines. Note that articles in magazines are advertisements. Some posts on forums are also advertisements.

I think they wanted them to look like the suspension linkage in dirt bikes and make you think you got progressive spring rates by using them. They are probably useful in some limited way but mostly a gimmick.