Front leveling = Rear sagging???

[evldave]

Originally Posted by cestwick

I guess I do not understand how a shackle lift raising the truck an inch and a half could effect ride quality if you still have same shocks, sway bar, springs, ect...

A shackle lift will likely cause more pivot for the leaf springs. Since suspension stiffness is a combination of everything you mentioned (shocks, sway bar, etc) plus the shackles, changing anything will affect stiffness. If you think of the leaf spring bolt swinging through an arc (with the top bolt stationary, but acting as a pivot), a longer shackle will allow more swing (longer arc). Since it allows more swing, even when driving on pavement, if nothing else changes, a longer shackle will result in the suspension system having less stiffness (because ever part moves all the time, more allowed movement=more motion=less stiffness). A less stiff suspension will result in a softer ride, but will allow more sway and susceptability to crosswinds.

I can verify this because it's common for XJ owners that offroad to get stiffer springs (I used Rubicon Express 4.5" lift springs) and eliminate the sway bars. If the leaf springs are stiff enough, you can completely get rid of the sway (but don't get into an accident or try and corner too fast!). Why do this? More flex offroad.

I've also noticed on my H3 that now that my stock shocks are getting toasted (too many gravel/washboard roads) my H3 is a lot more likely to lean over in the wind. Having a big roof rack doesn't help, but it shows that any component of the suspension can have a dramatic affect on driveability. Really there's no way to accurately predict exactly how much of a difference until you try.