[jdkilroy]

A few of us have recently noticed that the nuts on the main bolt of the upper control arm have become loose, if not actually missing after backing completely off.

The bolt in question:



So far, it seems that this has been a problem for those who have replaced their UCA's with the Light Racing UCA but anyone else who has had this issue should respond here so we can get a better understanding of the problem.

The torque setting for this nut is 85 ft-lbs and I am pretty sure that most folks doing this work have tightened to this value.

The question is why is the nut becoming loose ? There are no recommendations in the repair manual to indicate that Locktite or similar thread lock be used when assembling.

My own solution was to add a second nut to the assembly to prevent the first from turning



Anyone that has done work on their front suspension should check these nuts (along with all the others) especially if you replaced the UCA. If this turns out to be a problem unique to the Light Racing UCA's then they need to know about that.

Please post your experiences with this problem here.

[aha2988]

Just wanted to add that I've changed out my UCA's for the LR UCA's a while back purchasing an older design. I haven't had this nut come loose at all perhaps due to a difference in design.

Have you talked to SPC performance about this by chance?

[superman3043]

This issue was brought to my attention by @jdkilroy and boy am I glad he did. What I'm seeing so far is that it seems to point toward the new style bushings.

The old style are more like OE style. The rubber bushings that needed to be loaded before torquing them down. The new style (poly) ones seem to just basically turn and back the nuts out as the arm travels over time.

Be careful guys. Be sure to check this out. As I've said in my build, it would take a bit of doing for the pin/bolt to back all the way out. They are under shear force and the bolt would need to travel uphill, but it will definitely walk over time. Who knows how long mine was like that before I caught it.

[jdkilroy]

Originally Posted by aha2988

Have you talked to SPC performance about this by chance?

Not yet but perhaps I'll send a note so they could respond here if, in fact, this looks to be a consistent problem with folks who have done this work.

I got my UCA's in early spring of 2012 along with new suspension components from Overland Warehouse. Not sure of when they were manufactured and whether they are new or old style regarding the bushings.

[superman3043]

Actually Jon, looking at your picture, it looks like you have the old style... Kind of debunks my theory... Oh dear.

[aha2988]

Originally Posted by superman3043

Actually Jon, looking at your picture, it looks like you have the old style... Kind of debunks my theory... Oh dear.

These UCA's have been around for a while, I would imagine you would have heard of more instances of this happening but then again you would have never checked unless Jon had mentioned it. Just seems odd though.

[superman3043]

True... But just between Jon, myself, the guy who Alex actually witness the bolt back out on, and Keak mentioning it's happened to all of us, that's WAY more instances than I'm comfortable with. This is just people that have chimed in thus far. Who knows how many more like me that haven't checked there are. It's not something that would easily fail by design, but it could potentially be catastrophic.

[jdkilroy]

Sent SPC a note and will update with their reply.

Just to be clear: I am not suggesting that there is any kind of problem with the Light Racing UCA's. Right now, just trying to get a handle on why this might be happening so others can prevent it.

one thing to note is that a lot of folks do suspension upgrades who are not used to the notion of going back and regularly checking on things like the tightness of nuts and bolts etc. Once we stray from stock assembly and parts its on us to monitor the integrity of the work.

[BlackWorksInc]

Hmm... I'll have to check mine later today and see if they're loose....

[G.I.G.]

I installed my Light Racing UCA's about 3 years ago. After reading this thread, I just went down to my garage and checked the main bolt on both of my UCA's and they still seem to be tight. I have not torqued them since the initial install and everything seems to be fine.

As jdkilroy mentioned, it's always a good idea to go through your vehicle and inspect/tighten aftermarket suspension parts. The further you mod your vehicle away from factory components and specs, the more important this becomes.

[kkz]

I'd just like to add that this issue has also happened to me with my TC UCA's.

[ARK_SWAMP_RIDER]

Have any of you guys seen this? Seems like it was a freak thing, but something to watch out for.
Broken Light Racing UCA - Toyota 120 Platforms Forum

[jdkilroy]

Unsure how might be related (if at all) but the Radflo in that picture appears to be cranked down ~ 2x the max recommended (1.5").

[gaterose]

Checked mine this morning, they seem fine. I got mine about a year ago I think.

[jdkilroy]

Originally Posted by kkz

I'd just like to add that this issue has also happened to me with my TC UCA's.

As I mentioned earlier, this may just be an issue with taking apart the stock set-up. Its possible that they use some sort of a thread lock at the factory that none of us are using when we rebuild these.

Certainly no big deal to use Locktite when reassembling but would you need to let it set a while before subjecting the nut to rotational forces? And what would you use, Blue or Red?

If nothing else, this thread will get folks to go out and check their suspensions if they have ever done any work on them.

My Dad was a fighter pilot and he always said: "In God we trust... everything else, we check."