Both Rear Upper Control Arms Sheared off? WTF!

[comtn4x4]

Can't imagine the bushings you used had anything to do with your failure. Those bushings are designed to allow rotation type movement whereas the stock bushings are clamped solidly in place and movement is by torsionally twisting the rubber inside the steel bushing cup.
How did you remove your old bushings? Did you use heat in your removal process? If so, you could have used too much and caused metallurgical damage to the arms since the picture shows the failure appears to be at the weld.
Just a thought.
I bought some new OEM style upper arms for my '03 and cut the bushings out and installed Super Pro bushings, so I didn't use any heat.
So far so good, but I don't off road.

I think you're onto something here. I didn't do the bushings myself, I had a shop do them. I seem to remember they had a hard time getting the old ones out. I don't remember if they said they used heat or not but it seems likely. It was about three years ago so it's a bit fuzzy

 

[baldrik78]

Holy hell. I'm gonna have to go crawl under my truck and look at mine now lol

You got any pictures of the other side showing where the weld broke off?

 

[Charles Bronson]

Given all the mods to the truck, my guess is you have way more articulation than stock thus the trailing arms can be operated well outside of their design limitations. From looks of it, they twisted too far and simply snapped.

 

[comtn4x4]

Holy hell. I'm gonna have to go crawl under my truck and look at mine now lol

You got any pictures of the other side showing where the weld broke off?

I'll get some better pics as I go through the replacement process

 

[comtn4x4]

Given all the mods to the truck, my guess is you have way more articulation than stock thus the trailing arms can be operated well outside of their design limitations. From looks of it, they twisted too far and simply snapped.

This is very possibly it. The only thing I find odd is that it hasn't happened to anyone else? I don't think my truck had better articulation than others?

 

[blksubykid]

I've seen bolts back out but never the upper rear control arm shear. My only assumption would be that it was somehow damaged during removal of stock bushings and/or installation of new bushings...or maybe a weird combination of things previously listed

 

[Inv4drZm]

Yeah don't drive it like that at all. The only thing keeping your axle attached to your vehicle is your driveshaft at this point, hence the shuddering.

Once the driveshaft snaps you'll lose shock shafts, sway bar mounts, panhard bar, the entire axle housing... I've seen it happen to a 3rd gen on a trail, he posted on here years ago.

 

[comtn4x4]

Yeah don't drive it like that at all. The only thing keeping your axle attached to your vehicle is your driveshaft at this point, hence the shuddering.

Once the driveshaft snaps you'll lose shock shafts, sway bar mounts, panhard bar, the entire axle housing... I've seen it happen to a 3rd gen on a trail, he posted on here years ago.

Thanks for confirming. I'm not driving it now until I get it repaired. Hopefully the 10 miles I drove it didn't do any damage

 

[MidniteTRD]

while those bushings probably allow for pretty drama free rotational movement (unless their bolt got REALLY torqued down tight), i wouldn't be surprised if those links sheared from binding in axial rotation (think of articulation, one wheel stuffed and the other at full droop). without a certain degree of give the only thing left to twist is the metal shaft itself.

i don't know the durometer of these bushings compared to other aftermarket choices, but its a problem that can rear its head in other applications, such as sports cars, where stock bushings with engineered-in-compliance are replaced with performance bushings that are too stiff, which then cause bind which gets worse the further through the travel range the suspension cycles.

really glad it failed in a mostly drama free fashion for you....that could have been a Code Brown for sure.

 

[seatia]

while those bushings probably allow for pretty drama free rotational movement (unless their bolt got REALLY torqued down tight), i wouldn't be surprised if those links sheared from binding in axial rotation (think of articulation, one wheel stuffed and the other at full droop). without a certain degree of give the only thing left to twist is the metal shaft itself.

i don't know the durometer of these bushings compared to other aftermarket choices, but its a problem that can rear its head in other applications, such as sports cars, where stock bushings with engineered-in-compliance are replaced with performance bushings that are too stiff, which then cause bind which gets worse the further through the travel range the suspension cycles.

really glad it failed in a mostly drama free fashion for you....that could have been a Code Brown for sure.

Great Post :thumb:

Poly bushings are primarily for single axis use only.
Often the poly itself will split and crumble.
When more axis are involved a heim type joint is much better choice for a performance mod.

 

[Bmnorm2]

The last poly bushings I installed required grease and even provided a small packet of said grease. I believe it was silicone based grease.

Do you know if grease is required here and was applied by installer?

 

[MidniteTRD]

Great Post :thumb:

Poly bushings are primarily for single axis use only.
Often the poly itself will split and crumble.
When more axis are involved a heim type joint is much better choice for a performance mod.

thank you, and you said it more succinctly than me.

poly can be great in something like a sway bar or shock mount.

in a pillow-ball or control arm mount, you definitely need to be careful of bind, and aware that they'll likely wear out far quicker than a fresh rubber bushing. for off-road use i would never consider them, personally.

 

[comtn4x4]

The last poly bushings I installed required grease and even provided a small packet of said grease. I believe it was silicone based grease.

Do you know if grease is required here and was applied by installer?

They Stongflex bushings that are on there came with a packet of silicone grease. I didn't do the install, but I'll assume they used it.

 

[DigitalVex]

I'm going with no grease and 150+ lbs. ft of torque on those bushings.

Basically made it a solid upper link on the axle side with no up/down or flex. Metal finally gave at the weakest part.

Make sure you watch or trust your installers, lol.

Good luck out there!

 

[TRD PANTHER]

They Stongflex bushings that are on there came with a packet of silicone grease. I didn't do the install, but I'll assume they used it.

You added the Strongflex bushings prior to the upper links that broke? If so, I would question the install as DigitalVex mentioned.

 

[comtn4x4]

You added the Strongflex bushings prior to the upper links that broke? If so, I would question the install as DigitalVex mentioned.

Yeah I think that's it. The bushings have been on for about three years. I'm going to pull the old ones off tonight and I'll get a better look. New ones arriving tomorrow

 

[Bmnorm2]

I'm going with no grease and 150+ lbs. ft of torque on those bushings.

Basically made it a solid upper link on the axle side with no up/down or flex. Metal finally gave at the weakest part.

Make sure you watch or trust your installers, lol.

Good luck out there!

Exactly, this. Both sides failing after installing these bushings is no coincidence.

 

[Xtremluck]

Let the record show I was the first one to suggest this and was quickly shot down

 

[honda250xtitan]

Let the record show I was the first one to suggest this and was quickly shot down

no grease on poly? it wouldve squeaked like crazy. and to last 3 years? idk. could've been a freak thing. and nobody did anything wrong (except maybe poor driver mod) lol:reddance::reddance:

 

[Bmnorm2]

no grease on poly? it wouldve squeaked like crazy. and to last 3 years? idk. could've been a freak thing. and nobody did anything wrong (except maybe poor driver mod) lol:reddance::reddance:

Good point - she’d be a squeaker.

Didn’t see the 3 years comment until now.

But to his point, the significantly stiffer poly bushings will increase the peak and average stress in the rods. Maybe enough so to push them past the fatigue limit.

I would go back to stock bushings and rods or stay poly and acquire more robust rods.