Snorkeldepth

Before I pull the trigger on the next major wave of mods I figure I better go measure the distance between the rear lower A arm mounting positions at the frame. I know this is a common failure point with hard wheeling. I've never had a brace and intend to get one assuming my frame is within spec.

Does anyone have the spec for this? I need to know before tomorrow! Worst case I guess I could call Total Chaos tomorrow and ask them the dimension of their brace. I figure it's designed to fit pretty snug in between there.

Thanks

Snorkeldepth

I just crawled under the truck and measured the distance between the back bottom corners of the lower A arm mounts. It is roughly 17 1/4". Just in case that jogs someone's memory.

Snorkeldepth

Just in case anybody is wondering . . . . . my truck has been airborne more than once. Gotta love those desert whoops! O.k., it was only a couple times. (I never inhaled.) I figure it's worthwhile checking it out.

Scottz

17-1/4" is pretty right on. That's what mine is with alway's having a truss on it from day one.

Snorkeldepth

Thanks Scottz! I just went out and . . . :pat: . . . measured the distance between the front mounts that have a stock truss. Yep, . . . 17 1/4". What got me wondering was that all the camber/caster adusting cams are rotated outboard from 180 degrees by about 30 to 45 degrees except the right front cam that's dead on 180. That and the fact that I'm about to spend a bunch of money and I was running through everything I could remember about possible problems. Hmmm . . .

Scottz

Yeah, Alot of times I find the stock rubber bushing wear out and then you get a little whobble in the wheel that's not from the idler arm going bad. That may be the reason for all that adjustments on the lower a-arm. I know mine are getting bad, and a few weeks from now I have plans to build a long travel kit and get rid of all that rubber bushing crap. Scott

Snorkeldepth

Nice! I drool over the Total Chaos Caddy II system . . . . although I just saw the JD lower arm today and like how tough it looks. Good luck with your project. I hope it goes well and we all get to check it out when it's done. Thanks again!

rocket

iTrader: (1)

I had the same question: https://www.yotatech.com/forums/f31/2nd-gen-ifs-measurement-request-66868/

At 17.25" the rear lower control drop arms are tweaked, bent, spread apart, etc.
It don't happen from just hard wheeling either. The failure point can be a slow process that will simply take place with age. The correct mesurement should be at exactly 16 15/16" from wall to wall.

I just bought a Total Chaos truss and it's too short by 1/4". I called them and my 4Runners "failure" was confirmed.
If you read all the reaplies in the above thread, 17.25" seems a common distance but when others said 17" ...it made me wonder. So when i got my TC truss, i fully expected it to not fit.
Also, It makes perfect sense that over time those arms can and will spread 1/8" on each side and pretty much stay there. If hard off roading was added then you'd probably see or hear about cracks in the welds or at least further spreading.

A cheap solution given by www.offroadsolutions.com (where bought my truss) was to use a come-a-long to re-bend the drop arms back into factory specs. I'll be attepmting it soon.

Snorkeldepth

Hey Erik - I just now saw your response and checked out your thread. I'm a little baffled. I figured when I measured the front and found 17.25" where there's a stock truss holding the spread that everything was fine. Hmmm . . . . guess I'll go look again.

[Edit] Did you accomplish the fix you mentioned?

Snorkeldepth

Yep, . . . . baffled. I measured it again at the front lower a arm mount. The inside space measurement is 17.25 ". That's the spot where the front truss brackets are welded on. The truss bolts to those brackets. The truss has the front diff mount bracket welded to it. How could this dimension stretch with the truss? Wouldn't the front measurement be the same as the back measurement (i.e. the front and back of the a arm mount)?

Is it possible that there are different specs for different models or years?

Snorkeldepth

O.k., I'm a little less baffled . . . or at least not alone:

https://www.yotatech.com/forums/show...t=downey+truss

Creative searching strikes again!

Snorkeldepth

I talked to a guy at Downey today. Still, nobody can tell me why my specs are 17.25" front and back. Downey believed that their measurements were factory spec. After a long conversation we decided that the 17" truss would be best . . . even though it's for the earlier truck models. They measure from the outside of the plate on one side to the outside of the plate on the other. Allowing 1/8" on each side for the bends in the corners of the mounting bracket it should fit perfectly. Who knows if the holes will line up. The Downey guy said that quite a few guys weld these on. I'll let you know how it turns out.

rocket

iTrader: (1)

Hey Snorkel, I haven't done anything to my Runner for awhile but this spring/summer i'll be going crazy with mods and hopefully get this rear drop A-arm separation problem solved.

I did read that other link you found before but it hardly helps. I just found out Sonoran Steel is now making a BEASTLY TRUSS so i'm curious what his are measured out to be?

I know the guys at Total Chaos don't mess around and their truss appears to be stonger and better quality than Downey's truss and for the same price. They told me all 89-95 4runners should measure in at a hair less than 17" (inside wall to wall) and if its any more than 17" then there spread apart. I don't think measuring the front arms is suppose to tell you what the rear should be...it sure would be nice to know though.

I just took a couple pics of my T.C. truss to shed a little more light on this subject...

Snorkeldepth

Hmmm . .. 16 and 29/32" One point the Downey guy made was, "if you can align your truck then don't worry about it!" Maybe those are words to live by. If you can align the truck just bolt/weld in a truss and go! I'm not sure how beefy the truss needs to be. If I was an engineer I'd understand the structural needs in this application. But, since I'm not I can only speculate at the "pulling" as opposed to "compression" load which is a factor of, among other things, total potential downward force, the leverage created by the A arm mount, . . . among other things I lack the education to describe adequately. Maybe steel cable with a screw adjustment (like shroud tension adustments on sailboats) would be enough???

Thanks for the comments and the photos!

Let me know if you get the Sonoran specs.