Check this NOW if you have a 2021 Bronco -- cracks on rear control arm upper brackets

[popo_patty]

OP if you do end up letting your buddy weld it up, be careful if welding on your car. Even disconnecting the battery, a welder can still fry electrical components on modern vehicles.

Need to get the ground on the welder very close to the work area.

One of the guys I work with fried some components on his GMC recently when he was doing his exhaust and learned the hard way.

Good looking out! This guy is an expert welder and has been in off-road fab for 10+ years. We disconnect the battery and do nothing but the best ground lines to avoid frying a computer

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[NorthShoreBronco]

OH NO.... I better check my crack. will let you know.

 

[popo_patty]

Barnes makes some good stuff but it doesn't look like they offer the rear UCA top side bracket, just the axle side. Maybe after this discovery one will soon be in the works.

I already reached out and am waiting! So far it’s been 4 broncos that I have found cracked.

 

[popo_patty]

Flashbacks to being in the bad valve window

'21 SAS BL - Oct '21 build - No box but no crack....yet. Plenty of trails including Rubicon.

You have rust forming where the cracks form

 

[PWillette]

You have rust forming where the cracks form

Yep, not a good sign. Looks like the weld to the left isn't complete either.

 

[Fly by Nite]

The rust may be signs of the coating starting to fail due to flexing. Cracks may develop later.

 

[TeocaliMG]

So this Bronco has the worst that I’ve ever seen. It’s a first run of the 21, V6 Badlands from dirt mountain. The bracket was MESSED up. It was rewelded by the owner and then those broke as well. He is currently up in it, welding it again.

A while back there was a thread on broken axles and I was theorizing that due to the geometry, the lack of compliance (in tension/compression) in aftermarket arms may lead to binding. I removed/corrected my theory when others pointed out they were able to fully articulate practically by hand which would mean no binding. I also figured the geometry is too complex to simplify in just a 2D sketch.

These cracks have me thinking again. Especially if it seems to be limited to aftermarket arms. The image above is one such example of one of the more rigid options out there.

 

[popo_patty]

A while back there was a thread on broken axles and I was theorizing that due to the geometry, the lack of compliance (in tension/compression) in aftermarket arms may lead to binding. I removed/corrected my theory when others pointed out they were able to fully articulate practically by hand which would mean no binding. I also figured the geometry is too complex to simplify in just a 2D sketch.

These cracks have me thinking again. Especially if it seems to be limited to aftermarket arms. The image above is one such example of one of the more rigid options out there.

It is a theory I am considering as well! Thankfully, it seems that for most, Ford has gone to the boxed design which is not cracking. Why some have this open design… I have no clue but I want to figure out a way to box it in

 

[HotdogThud]

OH NO.... I better check my crack. will let you know.

Careful buddy, in your neck of the woods that can be dangerous

 

[akturbo]

2021, Badlands SAS, 2.7L, MetalCloak arms. Not a fan of the rust marks on the welds, I don't see cracks. Have cracks been found on the passenger side?

 

[popo_patty]

2021, Badlands SAS, 2.7L, MetalCloak arms. Not a fan of the rust marks on the welds, I don't see cracks. Have cracks been found on the passenger side?

Yes, mine are cracked over there as well.
As far as the pic. Look closely but I spy crack. That’s exactly how mine started

 

[broadicustomworks]

It is a theory I am considering as well! Thankfully, it seems that for most, Ford has gone to the boxed design which is not cracking. Why some have this open design… I have no clue but I want to figure out a way to box it in

I'm thinking order the simple parts nut plate/captive nut present on the capped version and use some 1/4", box that puppy in and use the new captive nut insert....basically mimicking what Ford did on the revision but in a bit thicker metal.
Plus most of my scrap I can get readily is all 1/4" and thicker, so it's an easy decision for me.

 

[UncleBuck]

‘21 badlands 2.7, Sas, Tow Package. Built on 12/7/21 and delivered on 12/23/21.
Looks boxed and not rusty. Doesn’t look cracked.

 

[akturbo]

Yes, mine are cracked over there as well.
As far as the pic. Look closely but I spy crack. That’s exactly how mine started

Sh!t, I only had a few minutes to look, I'll get back under there later (not in street clothes) for a closer look.

 

[GreyZ]

Have any seen cracks with oem Upper and Lower control arms. These cracks don't seem like they would occur with forward and aft movement. Seem to be caused by seperation/torsion of the two mount faces which would occur with increased articulation.

Solid sphericals/johnny joints at the rear control arms would allow for undampened flex right to the max articulation and could allow for impact loading of those joints in rotation which would put insane seperation/twisting forces on those mounts.

Either way, if you go to reweld it I would make sure to put a plate on thhe bottom to atleast partially box it.

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