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

AssBurns

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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

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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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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

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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

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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

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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:
 

kasnerd

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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:
ya think you'd have learned the first two times.
 

Dezert4Runner

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What’s left for him to run off the shelf for the front? Solo XLT? Or is he thinking of going custom built?
 

AssBurns

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What’s left for him to run off the shelf for the front? Solo XLT? Or is he thinking of going custom built?
Not 100% sure. Possibly ditch the 4wd and go with something like the Camburg race kit or I think MCM might be coming up with some sort of a race kit at some point too. Not 100% sure on it, but it’s just ideas at this point.
 
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Dude, I watched the Youtube video on this last night... holy smokes. Being pretty fresh to this scene, I'm blown away. Will he put any of the interior back in? Or basically just the front seats? I've been following along the whole time but didn't realize you guys chopped so much of the frame. Subbed for sure!
 

AssBurns

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Dude, I watched the Youtube video on this last night... holy smokes. Being pretty fresh to this scene, I'm blown away. Will he put any of the interior back in? Or basically just the front seats? I've been following along the whole time but didn't realize you guys chopped so much of the frame. Subbed for sure!
Thanks for watching! Glad you are digging it!
Not 100% sure how much of the interior he is going to put back in. The plan as of now is to have at least a bucket seat in the back. I don't think there is enough room between the shocks to do a narrow bench seat, plus it probably just wouldn't be advised to do anything besides a bucket seat back there.
The plan is to try to seal the cab as much as possible. Since I'm not doing the cage or body work, I can't say exactly what the plan is because neither of us know at this point.
 

AssBurns

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More progress. Almost done with my portion of the build. So stoked to see this thing get finished and hit the desert.
Today we got the bump stops welded in, bump strike plates made, limit straps on, and swapped to a longer sway bar arm to get better geometry at full droop.
From here it’s going to Tommy at TT Motorsports for the cage, sheet metal work, and front long travel. This is also getting a LM7 5.3. Not sure if Tommy is going to do that swap or if someone else will handle that portion.


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@AssBurns
The TK1 bushing come with 4 washers that have the same I.D. of the sway bar, what r they 4...., 1st I was thinking one on each side of the spindled arm to bar mount but that doesn't seem right from the pics I can find... been looking online but so far haven't seen any set up that seems to use them unless they r behind the bar/arm bracket
 
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