Both Rear Upper Control Arms Sheared off? WTF!

[comtn4x4]

Thanks for that link. It was a very interesting and informative video on the KDSS system. That helped a lot. I always hear the pros and cons of the system, but I honestly don’t pay much attention since I don’t have it. I see the pros. What are the cons?

I think 02SE hit it pretty well. One additional plus I rarely see mentioned is if you carry a lot of weight on your roof rack or have a RTT KDSS will be a godsend.
My opinion is lifting with KDSS up to the 3" is threshold requires no more thought than lifting a non KDSS rig up to that same height. (Which is how almost all 4runners are lifted) KDSS blocks aren't necessary unless you're neurotic about the lean and the KDSS switch isn't necessary but it's really nice. (All these KDSS improvements are relatively new in terms of how long KDSS has been available. ) Where KDSS gets complicated is if you want to be lifted and have it preform REALLY well, full potential droop in the rear end and return the system to level front and rear. And it gets really complicated to do a long travel set up, debate-ably not worth it.

 

[baldrik78]

I do have the Sonoran Steel KDSS adjustable trac bar. It's positioned as it is supposed to be. I also have a KDSS spacer block. Are they what is causing the issue? Good question, I don't think so bit it's certainly possible.

It could be a combination of the added flex from the trac-bar/KDSS spacers with the less flexible poly bushing.

Products that look good in a vacuum can have vastly different outcomes when stacked with another non-oem product.

 

[jbtvt]

From your pics showing intact paint it doesn't look like those arms were heated to remove the old bushings, and it wouldn't be expected. The shop would've been a cloud of black smoke from burning rubber long before the metallurgy was affected. Map gas will burn off paint pretty easily and it's hard (impossible?) to get a piece that size anywhere near red hot with a standard tip, oxy acetylene torches paint almost instantly

 

[comtn4x4]

I was e-mailing with Steve from Sonoran Steel the other day about this and here's his take on it:


"As for the links coming apart, yes I have seen that before. But not how you think. In the year 2000 with the 3rd gen 4Runner Toyota had issues with the welding on the upper rear links. This only happened to model years 2000-2002, in that case the weld on the end tube did not penetrate. In your case the weld did not penetrate the small center rod.

If you look at the breaks they had rust in them prior to coming apart. The small silver areas are where the welding penetrated the center rod, these are the areas that actually held them together. If these were welded correctly, then the bushings would have sheared and split from over twisting. You could clean them up and re-weld by someone who can weld correctly and then side twist and spit the bushings. Toyotas part supplier probably uses a computer welder but the machine/robot seems to be set wrong from time to time lacking penetration and they don't seem to do destruction QA testing.


The upper links came apart because of very poor welding. That is disappointing that they are still having this happen. There is no way a soft poly bushings will hold up to welded steel, the poly will fail first."

 

[jbtvt]

I think he's mistaken. Those welds look good to me, and though we can't really tell from the photo angle, the break appears to be through the solid bar stock itself above the weld. The only way you'll get that "high cycle low stress" fracture pattern as jetboy so eloquently described is if the weld is holding and the bar itself is being torqued beyond its yield point. The rusty one I thought was established was likely broken for a while and you didn't notice symptoms until the other one also gave out.

 

[comtn4x4]

I think he's mistaken. Those welds look good to me, and though we can't really tell from the photo angle, the break appears to be through the solid bar stock itself above the weld. The only way you'll get that "high cycle low stress" fracture pattern as jetboy so eloquently described is if the weld is holding and the bar itself is being torqued beyond its yield point. The rusty one I thought was established was likely broken for a while and you didn't notice symptoms until the other one also gave out.

That's very possible. I'm not sure if we'll know for certain.

 

[jdm-v35]

I haven't driven it too much yet. That being said not significantly different. Possibly a bit smoother through the travel. I'll need to drive it some more and get it off road. It appears the driver's side arm was broken longer than the passenger side so I've been running with one for an undetermined amount of time. I sort of interested to see if I notice a difference with both installed

I know its been a while but just curious if you are still just running the passenger side arm? or put both in? and any significant difference in just running one arm?

 

[comtn4x4]

I know its been a while but just curious if you are still just running the passenger side arm? or put both in? and any significant difference in just running one arm?

I have been running just the passenger side arm consistently since early spring. I went back and forth only passenger and both a couple times to see if I could tell a difference and there's no notable difference I could identify. As [MENTION=137195]honda250xtitan[/MENTION] suggested going with the passenger side only seems to be a good way to go. That being said I am running a significantly upgraded UCA with Heim joint, not sure how that would compare to the OEM UCA.

 

[jdm-v35]

I have been running just the passenger side arm consistently since early spring. I went back and forth only passenger and both a couple times to see if I could tell a difference and there's no notable difference I could identify. As [MENTION=137195]honda250xtitan[/MENTION] suggested going with the passenger side only seems to be a good way to go. That being said I am running a significantly upgraded UCA with Heim joint, not sure how that would compare to the OEM UCA.

Thanks for the updated info. I am looking at upgrading both my lower and upper links as well so was just debating whether the passenger side only upper link is the way to go. I have the extended travel metaltech Icon 2.5's and was able to flex it out pretty hard on my last trip so trying to strengthen and optimize my setup.
I was able to fully compress the driver side and fully flex out the passenger side and my passenger tire was still a foot off the ground as I was leaning over a cliff on the driver side. Since a lot of the offroad places I do go are sketchy washed out cliffsides like that I figured I would try to give myself any strength and capability advantages possible.
Did you notice any additional travel gained by passenger side only?

 

[comtn4x4]

Thanks for the updated info. I am looking at upgrading both my lower and upper links as well so was just debating whether the passenger side only upper link is the way to go. I have the extended travel metaltech Icon 2.5's and was able to flex it out pretty hard on my last trip so trying to strengthen and optimize my setup.
I was able to fully compress the driver side and fully flex out the passenger side and my passenger tire was still a foot off the ground as I was leaning over a cliff on the driver side. Since a lot of the offroad places I do go are sketchy washed out cliffsides like that I figured I would try to give myself any strength and capability advantages possible.
Did you notice any additional travel gained by passenger side only?

I didn't do any qualitative comparison so definitively I can't say. Seat of my pants, it seems to flex a bit better but it could be in my mind.

As far as upgrading the upper arms goes, I seem to be the only person to ever destroy their upper links on a 5th gen so I'm not sure it's worth the $. It has been said that they don't endure much stress. The lower arms I personally think it's best to wait till they get bent (If they do). But I'm a break it then upgrade it kind of guy.

 

[jdm-v35]

I didn't do any qualitative comparison so definitively I can't say. Seat of my pants, it seems to flex a bit better but it could be in my mind.

As far as upgrading the upper arms goes, I seem to be the only person to ever destroy their upper links on a 5th gen so I'm not sure it's worth the $. It has been said that they don't endure much stress. The lower arms I personally think it's best to wait till they get bent (If they do). But I'm a break it then upgrade it kind of guy.

I am trying to be proactive if possible especially after my experience this past week and the scare of being stranded with no reception and 70 miles from the nearest civilization and >300 miles from home. If you saw my other thread about TB failure, I am feeling even more cautious. I also have bent a front alignment cam tab already and hammered it back and got an alignment again. I have the marlin crawler cam tab reinforcements and RCI rear link skids in the garage waiting to be welded in once I have time as well.

I have learned that being prepared has helped. I also had to change my friend's alternator out there in the forest and luckily we carry full tool sets to do so.

I do have a garmin messenger in case, but a tow would probably cost way more than proactively buying the parts. Even for just the uhaul and trailer it cost me $400 to tow myself home from Craig.

 

[honda250xtitan]

I have been running just the passenger side arm consistently since early spring. I went back and forth only passenger and both a couple times to see if I could tell a difference and there's no notable difference I could identify. As [MENTION=137195]honda250xtitan[/MENTION] suggested going with the passenger side only seems to be a good way to go. That being said I am running a significantly upgraded UCA with Heim joint, not sure how that would compare to the OEM UCA.

thats good to hear. I wouldnt run OEM arms with just 3 of the links.

 

[jdm-v35]

I didn't do any qualitative comparison so definitively I can't say. Seat of my pants, it seems to flex a bit better but it could be in my mind.

As far as upgrading the upper arms goes, I seem to be the only person to ever destroy their upper links on a 5th gen so I'm not sure it's worth the $. It has been said that they don't endure much stress. The lower arms I personally think it's best to wait till they get bent (If they do). But I'm a break it then upgrade it kind of guy.

Wanted to follow up and see how the single arm thing is working out so far? any advantages/disadvantages? I Just did my lower arms and replaced with metaltech, and have the metaltech uppers to put in, just debating if I should put in both or just the single one.

Just replacing the lowers the OEM seem way flimsier than I would have thought, for the size they look. They were relatively light when off the car. The metaltech Lower arms are about 2x the diameter and 4-5x the weight.

I had the new arm sitting around for a few months and glad i finally had time to install them as it seems to be a significant strength upgrade. Can't wait to do the uppers!

 

[comtn4x4]

Wanted to follow up and see how the single arm thing is working out so far? any advantages/disadvantages? I Just did my lower arms and replaced with metaltech, and have the metaltech uppers to put in, just debating if I should put in both or just the single one.

Just replacing the lowers the OEM seem way flimsier than I would have thought, for the size they look. They were relatively light when off the car. The metaltech Lower arms are about 2x the diameter and 4-5x the weight.

I had the new arm sitting around for a few months and glad i finally had time to install them as it seems to be a significant strength upgrade. Can't wait to do the uppers!

Still running single arm and having no issues. That being said I didn't have issues I was aware of before other than destroying the stock arms. I see no reason to hold back on running one arm only. As far as advantages/disadvantages, theoretically the driver side arm could hit the gas tank at full droop so you are eliminating that possibility. I don't see any evidence of that happening in 11 years/150K miles.

As far as the lower arms go, the issue I had was bending them, so a beefier arm is a great upgrade. I'd get some armor on the frame mount as well. Metaltech is a great company, highly recommend their stuff.

 

[jdm-v35]

Still running single arm and having no issues. That being said I didn't have issues I was aware of before other than destroying the stock arms. I see no reason to hold back on running one arm only. As far as advantages/disadvantages, theoretically the driver side arm could hit the gas tank at full droop so you are eliminating that possibility. I don't see any evidence of that happening in 11 years/150K miles.

As far as the lower arms go, the issue I had was bending them, so a beefier arm is a great upgrade. I'd get some armor on the frame mount as well. Metaltech is a great company, highly recommend their stuff.

Thanks for the info! good to know it is still holding up fine. I did notice that the driver side does get close to the gas tank and with how thick the metaltech arm is, it would be cutting it very close since I have their rear LT kit.

I do have the RCI rear mount skids, but haven't put them on because it looks like with the thick metaltech lower arms they may hit on full droop. What skids are you running and any issues with fitment like that?

 

[comtn4x4]

Thanks for the info! good to know it is still holding up fine. I did notice that the driver side does get close to the gas tank and with how thick the metaltech arm is, it would be cutting it very close since I have their rear LT kit.

I do have the RCI rear mount skids, but haven't put them on because it looks like with the thick metaltech lower arms they may hit on full droop. What skids are you running and any issues with fitment like that?

I have the Metaltech OPOR Lower Link Guards. I haven't had any issues and they've been on for about 3 years