Both Rear Upper Control Arms Sheared off? WTF!
 

Like the title says, truck started making some weird noises/shudders this morning so I got underneath and found both the OEM rear UCA's sheared off at the rear pivot. I was under the impression these didn't usually have issues? 120,000 miles FWIW and upgraded bushings probably 40,000 miles ago.

So two questions here:
Safe to drive? There's a definite driveline shudder from a stop then it settles down.And some suspension noises unsurprisingly.

And of course replacements? I'd prefer to stay low maintenance so probably not a Heim joint. I already replaced the lowers and the trac bar so a kit won't be needed. Oh and in stock would be mandatory obviously.

I see OEM for $90 (Each I think)

Moog for $298
Icon for $400
Dobinson's for $305
Total Chaos $687
Metal Tech $375


Who's replaced these and what route did you go?
Anything else I should be looking at while I'm in there?

Personally never seen this. I only upgraded mine because it came as a set from Resz Fab (now out of business). I was only looking to upgrade my lowers since those tend to bend when wheeling. Their price for the poly set was great but their customer service and lead times were TERRIBLE. Sonoran Steel even suggests just to upgrade the bushings on the stock uppers rather than buying aftermarket ones.

If I were to do it all over again, i probably go with either Dobinson (they also have offset uppers) or Metaltech (proven).

I regularly check the bolts on my suspension because on several occasions I have found them to come loose, including the uppers. I assume it would be safe to drive short distances but I personally wouldn’t risk it with it completely sheared…

Yeah I was thinking the same about driving. I'd like to go Metaltech too but they're out of stock I realized.

Overland Custom Design uppers look relay solid and a reasonable price and in stock too. Plus @MStudt is a user here.
Upper Control Arms
– Overland Custom Design

I run metal tech and a buddy runs BuiltRight Fabrications upper and lower rear links.

Both are good to go.

I went with metal tech because its reasonably priced. Nothing negative to say.

I think metal tech makes to order, so it took about a month to receive mine.

I'd get whatever is in stock so you don't have too much down time.

I would be curious what in the parts or the use or combo thereof may have caused this before I choose replacement.

Maybe I should inspect mine cause we have not been gentle to the truck in the desert. Could the tire weight have been a factor? At 66lb yours are much heavier than stock but then again everybody runs 55-65lb tires so...no idea, just thinking aloud.

If there is no obvious reason to worry, I would go OEM given the prices but if there is a significant difference from OEM specs maybe not....

Yeah I've had good luck with other Metal Tech stuff but waiting is a no go. I checked out BuiltRight and they don't even list 4Runners on their site, only Toyota was Tacoma. Must not make them any more

This is my question/concern as well. Their doesn't seem to be a lot of instances of these failing so IDK. I was wondering if the bushing seized on one? But to have both go seems odd. I don't think I run any bigger/heavier than anyone else. Actually I'm pretty sure it's the opposite. I also don't think I push my truck too awful hard but maybe I'm wrong. I wonder if when I bent my rear lower control arm it damaged the weld on that side. It was quite bent, probably an inch or so. I'll get a better look at them when I take them out.

I did notice the ends of both arms aren't rusted so they must have sheared off relatively close time wise.

As far as the OEM goes it would definitely be cheaper to go that route and after all they did last 120,000 miles. However, I did notice a big difference when I upgraded the bushings on all the rear links. Much smoother travel.

I'm leaning towards the Overland Custom Design arms. Look very solid. Might even change my lower arms to those too.

If you have any questions let me know. I have these boxed on the shelf and ready to ship.

Mike

give BuiltRight a call. They don't update their website often since most of their business is local peeps like myself.

I think they make their links in chromoly, which is a step up from metal tech...but double check with them.

dang those look fantastic

Yeah, I mean, with one, stuff can happen, but both?

On one of the several rear spring changes in my hot AZ garage, I forgot to undo the rear sway bar links...so ended up with one new link and one that is a little bent but ok.

Is it possible you did something that overstressed both sides at once?

Wild. Never seen this on any gen although I did lose a threaded rear trailing arm on a '99 camry once 10-15 years ago. Poly bushings are usually stiffer than rubber and that one looks really tight in there, so the lack of flex is probably what did it. Also want to make sure your vehicle is at ride height when you install something like this, but even if it was, if things can't move the way they were designed to something is gonna give.

This video may have answered some of my questions on the lower and upper rear links. What do you think?
5th Gen 4Runner- Our Choice & How To Install HD Rear Lower Control Arm, Toyota - YouTube
This info is from the Sonoran Steel website:
“Why don't you make custom upper links? The best replacement for the upper links is re-bushing your current stock links with the replacement Strong Flex bushings we sell or new stock upper links from the dealer. The reason why is that you can not make either the lower or the upper links longer than that are, because the upper link brackets on the axle tube already clear the Panhard/trac/lateral bar cross-member by millimeters. Longer links will collide on compression causing catastrophic damage. The upper links will never get hit by rocks and the stock units side twist quite well. The small diameter solid stock will also twist like a torsion bar.
FYI: The first few years that we made lower links we used Rubicon Express, Currie Johnny and Summit Machine socket joints. While these joints did have good side twist movement, the problem was that they wore VERY quickly. Rebuilding the cartridge every year is not something we are interested in. The stock Toyota joints listed above side twist just as well and are maintenance free for an extremely long time.”

OP: buy one aftermarket upper. install on passenger. run it like that and see how it feels. you wont need to worry about hitting the fuel tank at full droop if you don't have a driver side linke ;)

There is definitely something going on here. Maybe those upgraded bushings were too stiff and eventually fatigued the OEM links to the point of failure? I'd personally would just go OEM with stock bushings as a fix for this.