Toyota Hilux / Surf / 4Runner Falcon Spring Swap
This is a brief overview of the falcon spring swap. If you are sick of getting no flex from your leaf-spring-rear Hilux or Surf then this could be the swap for you. Its relatively cheap considering the performance boost it gives your rear end, and the increase in ride comfort makes it almost worth doing even if you're not going offroad that much. In a nutshell, you need Ford Falcon spring packs from a ute or a wagon - I don't recall the models: early to mid 80's tho. They are recognisable as having 4 or 6 leafs (6 is preferable but not critical), and being hellishly long.
The spring pins are offset too much to use as they stand - so the main and second leafs need to be re-drilled approx 115mm closer to the centre of the pack, all the other leafs can just be turned around and they work fine that way. Note the approx value here... Its because what is critical is where your tyre goes when its being stuffed up inside the guard - if you're running 35's or bigger then you want the wheel absolutely dead centre of the wheel arch (assuming a surf here) or you're gonna eat metal... not good for the bodywork or the tyre. At the end of the install you want to position everything to make sure the tyre is where you want it before you finally weld anything. As a footnote: for your own sanity, get a springmaker or an engineer to drill the holes for you... you will most likely re-sharpen 3 or 4 drill bits to nothing before you get the 4 leafs done... 20 year old work-hardened spring steel is an absolute bastard to drill through...
The front spring hanger is a simple affair. I can make you a set or you can make them yourself... see the pictures for an idea of what you are doing if you are making them yourself. As a guideline, the inside plate of the hanger should be roughly in line with the inside of the chassis rail, and the out-hanging portion should be braced as shown for strength. The hole at the front of the pack is for a 1/2" bolt.
The rear hangers will need to be moved back a bit (40-50mm approx) and brought down (50mm-ish) to set the ride height (to avoid having unduly long rear shackles). The shackles will need to be custom made to suit the hilux top bolt and the falcon lower one. Once again we can make these for you if neccessary. The shackles should sit at around 45* at rest to allow for best flex and droop - straight up and down is better for handling, but hey - why are you doing this swap... for flex or for on-road performance?
As you are fitting a spring with a 65mm width you will not be able to use the square u-bolts from the hilux pack (Hilux springs are only 60mm wide). a u-bolt flip will be required - some 10mm plate and 2 round u-bolts (we can supply just the bolts or a complete kit) will do this.
Then the shocks need remounting - pins on the axle housing and the round crossmember above will suffice - get some long travel shocks, you'll need them... Maxitrac 6023's are a good choice here.
I hope thats helped in some way - its not a definitive step-by-step - if you need that then you should probably have us do the conversion for you - its an overview of the parts and process. I'm happy to discuss undertaking the conversion on your behalf, or supplying parts, or perhaps doing the welding component of the swap for you, but I'm unlikely to break the process down any further here. Good luck and happy flexing.
