god i love this write up on springs hahah. oh and was wondering, im kinda newbish rig i have now is my first build. but if u could do a few more bullets on like different bushings and little more detail on shackles shackle angle double shackle or tera flex etc. idk unless theres already a thread up on that
Bushings, just grease and replace them every other season of wheeling, or maybe go 5 years on a DD or mild trail rig. I've always had great luck with the Polyurethane bushings that almost every aftermarket Toyota vendor sells. Use a flex hone with a 1.25" OD to clean out old spring eyes to get all the rust and crud outta there.
Shackle angle was covered, but basically you want a 30-50 degree angle depending on the free arch and amount of sag your springs take with the weight of the vehicle.
I've never messed with a double shackle, or any other "alternative" shackle mount, like say a spherical eyelet bearing mount. I've always had great luck with the more traditional setups, and really just heard too many bad stories about non traditional systems.
The best shackle is one that utilizes a sleeve spanning the width of the 2 bushings plus 1/8" with an OD to match the bushing hole, usually 18mm on our Toyotas, and an ID of 9/16" rather than a big 18mm bolt. This allows you to tighten down your bolts nice and snug without crushing your bushings, very effective, great ride quality, longer bushing life, and much better flex, too. This also eliminates the need for a welded in cross tube from shackle plate to shackle plate.
I really love 5" shackles with soft, high arch springs that flatten out quite a bit when the vehicle is on all 4 wheels. I also like very firm dampers, which tend to work well with this setup, since the springs themselves are usually quite soft.
