Robert's Trailing Arm 4Runner (Down the Rabbit Hole)

AssBurns

will wheel for beer
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#1
Since Robert doesn't do forum stuff, I figured I'd throw updates on the build progress on here since I'm helping out with the build. Not wanting to clog up any tech threads for updates. I'll try to do some photo dumps and updates here as we go.

Some background on the build. Robert bought this rig to drive around while he was working on a SAS on his black 3rd gen. Next thing you know he bought an MCM Long Travel Kit, bumpers, sliders, skids, 35's etc. Well his black rig was taking forever so this build kept going down the rabbit hole in the meantime. He somehow convinced me after about 6 months of nagging to help him with his rear 4-link since I did it on my 3rd gen a few years prior and it worked very well.

So as of May of 2020 we did dual triangulated 4-link, notched the frame, added 2.5" x 14" coilovers and 2" x 2" hydro bumps. It performed really well, but he also wanted to add bypasses to the rear like he did up front. At first the plan was just redo the frame notch to fit bypasses and add a fuel cell instead of the F150 tank swap. Then came the idea of trailing arms instead...
...and down the rabbit hole we went.

Most people do trailing arms on the outboard side of the frame rails, but this leads to not the best geometry or ground clearance. We wanted more ground clearance, and in order to maintain better geometry, we needed to triangulate the lowers for better roll axis angle (less roll steer). Well for us to add triangulation, we had to mount the lower links right were the frame rail sits. Our plan? Chop off the back 51% of the frame rails and put the links where the frame used to be. We made a new back half of the frame out of 2" x 4" tubing and moved the rails in about 4.5" either side (total of about 9" narrower overall).

Currently we are working on getting shock hoops done, and waiting for fuel cell cradle, axle side upper link mounts, and shock mounts to get cut, bent and shipped.




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AssBurns

will wheel for beer
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#2
Got some parts and finished welding up the trailing arms. Didn’t get much for pics besides the few I shared on IG. The TK1 sway bars are multi piece and the fitment is super tight. I left the parts in the freezer for a couple hours and it fit a little easier. Still needed some whacks with a deadblow to get into place.

also got the shock mounts and fuel cell mounts I drew up and had Caleb at Hot Metal Fab cut and bend for us.



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#3
Have you found any guides or information on sway bar selection and installation guidelines? Seems like the whole thing is just tribal knowledge and "this looks OK, hopefully it doesn't break".
 

AssBurns

will wheel for beer
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#4
Have you found any guides or information on sway bar selection and installation guidelines? Seems like the whole thing is just tribal knowledge and "this looks OK, hopefully it doesn't break".
TK1 has some good basic info on their site. There are some threads on PBB about sway bars. There is a lot to sway bars but also a lot of it is subjective to people’s driving style and suspension geometry (front and rear) so some info has to be taken with a grain of salt. Luckily a sway bar can be tuned. Shorter or longer arms, or softer/stiffer bar.
 

AssBurns

will wheel for beer
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#6
Finally made some progress again on this thing. Got the fuel cell mounted up. Most of the body mounts are on (I lost a bushing so we didn’t get the last one on).

Last weekend I welded up the upper link mounts on the 9” axle. Didn’t get pics of the finished product but I also made some bracing off the back of the axle to support the link mount from ripping off.


http://instagr.am/p/CTv4tckrg2S/

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AssBurns

will wheel for beer
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#8
That is looking good. Let me know when it goes into production I’ll be the first one to order the kit and I don’t even own a third Gen.
Lol I don't think it would be a good seller. Why someone want's to build a 3rd gen 4runner is beyond me...

...Say's the guy that's dumb enough to own two of them. :deadbanana:
 
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