One of my goals for our FZJ80 is to keep a relatively low frame height while maintaining as much up-travel as I can. I’m pursuing this in stages; first a 50mm lift to get the travel benefit of longer shocks and springs, then a 1″ body lift to increase the overhead room in the fender wells for larger tires, and eventually 37 or 38s.
Since I’m only lifting 50mm, I decided to pursue caster correction by lowering the frame side radius arm mount by the same 50mm to return both the caster and the anti-dive to factory specs. I looked around and found a bolt-on option to do just this; but that product is larger than I’d like, and I’m a big proponent of weld-on solutions. The other aspect that I was interested in was relocating the axle forward to create more firewall clearance for larger tire sizes.
So, I’ve made some Radius Arm Mounts to relocate the frame end of the FJ80 series radius arms down 50 mm for a 2″ or so lift and 30mm forward for big tire firewall clearance (and to improve approach angle)
By making them weld-on, I’m able to run a reinforcing plane/rib up into the rear of the factory mount, increasing the weld area and tying everything together as a single structure. This also allows me to keep these mounts as svelte as possible so that any obstacle that the arm might slide over will not get hung up on the mount extension.
And even though they are weld-on, they do not obscure the stock hole, so if you change directions (not everyone is as concerned about not increasing anti-dive as I am) you can trim off the lower part and still have a reinforced factory mount for your trouble. 🙂
(but I don’t think you’ll end up doing that)
*the front axle is relocated 30mm forward (maximum) on this first run of mounts, which is great for firewall clearance for 38+ tire sizes but expect some fender trimming in the front with those larger sizes.
*at 30mm of relocation, grinding or clearancing the weld bead on the differential or use of aftermarket offset bushings may be needed to clear the panhard bar during articulation, depending on your suspension setup. (I’ll make a version with less axle relocation/more differential clearance when I have compiled more data about where the sweet spot is for the smaller tire guys )
*I recommend using an old/spare radius arm bushing as a spacer along with the factory nut and bolt to hold the factory mount solid while tacking the RAM in place; then moving the bushing/bolt/nut down to the RAM to hold the ears parallel and coplanar with the inner walls of the factory mount for welding. – great excuse to finally get around to replacing those factory bushings!