Lower control arm snapped while reversing - 06 GT

[metrolink]

Hey everyone,

I have a 2006 Mustang GT. Yesterday I got two new front tires replaced. The car drove fine afterward, no clunking or any sounds. Later that night, as I reversed into my parking spot with the wheel turned all the way to the right, the passenger-side lower control arm snapped clean at the knuckle side, and the wheel collapsed inward.

The driver's side looks completely fine. No potholes, no curb hit, no impact. This literally happened just backing in to reverse park.

I called the tire shop manager, and he said they "lift from the pinch welds or use the lift points" but of course I didn't actually see how it was lifted this time. They want me to tow it to a shop so they can inspect it and decide on a claim.

I'm thinking of just replacing the parts myself to save the headache, so I'm mainly looking for insight:
My question is how could a control arm snap like this? Is this more likely metal fatigue, or could improper lifting actually cause this kind of delayed failure?

 

[JC SSP]

I doubt that was done at the shop. GT control arms are known to fail but usually when driven hard.

Just buy two GT500 control arms and you will set for many years.

 

[Samos3]

That is the failure that caused the arms to be upgraded and superseded by the GT500/Boss302 arm.
You can compare the arms on Rockauto.
Look at the non-oem arms compared to the Motorcraft replacement arms. The revised arm is much beefier. Just make sure you get the upgraded arm for the 05-09 as the later arms have a bigger balljoint.

Edit: I'm assuming that failure is why Ford went to the upgraded arm as the factory replacement for the V6/GT. Ford apparently felt the need for the heavier duty arm on the GT500 and Boss 302.
But then again, they might have figured why continue making two items to inventory when one will cover all applications and one has a failure mode...

 

[Miker]

 

[GriffX]

When I see this picture, I noticed that there are long holes at the hydro bushing. Does that means that you have to go to an alignment shop when you change the arms? Caster is changed?

 

[Miker]

When I see this picture, I noticed that there are long holes at the hydro bushing. Does that means that you have to go to an alignment shop when you change the arms? Caster is changed?

I don't think so. When you torque down the front mount the position of the rear mount is set. At least that is how I did it. I also positioned it it the position it is in when the weight of the car is on it before torquing it down. I took some measurements when the car was on the ground with the old arms and then set the new ones to that position before torquing. Also flipping the flag nuts on the rear mount allows access for the torque wrench.

 

[JC SSP]

I would recommend an alignment check!

 

[Samos3]

When I see this picture, I noticed that there are long holes at the hydro bushing. Does that means that you have to go to an alignment shop when you change the arms? Caster is changed?

I don't think there is really any adjustment at the arm for caster. The forward bushing sets the position of the arm. The slotted rear holes might be to allow for any variance in fabrication of the crossmember or the rear bushing/mount.
When I did mine I replaced struts and springs (Ford Racing .75"/1" lowering), so I was headed for an alignment anyway. But probably not a bad idea depending on how it feels after you are done.

Honestly, they probably lifted the car correctly. And since it is a known failure point, I wouldn't bet on them accepting a claim, but you never know. If they reject a claim you'll not only have to cover the tow bill to them, but then what? Tow it back ($) and then do it yourself? Or spend more for them to do it 'since it's there'. If you are comfortable doing the replacement and can do it where the car currently sits, if it was me, I'd buy the arms and replace both.

 

[StockishS197]

I would recommend an alignment check!

When I swapped my stock control arms for GT500s, my caster did change slightly, though there isn’t any adjustment you can make in the arms AFAIK. The alignment shop had to shift my cradle slightly to get it within spec, so definitely get an alignment.

 

[GriffX]

I found a Ford eccentric bolt kit, the bigger bolt is for the strut and the smaller goes where?
(I want to change the arms in winter storage, the hydro bushing has lots of surface cracks)
Without these bolts no alignment shop will do anything here and the toe I can adjust myself.

https://performanceparts.ford.com/part/M-3B236-A

 

[Samos3]

I found a Ford eccentric bolt kit, the bigger bolt is for the strut and the smaller goes where?
(I want to change the arms in winter storage, the hydro bushing has lots of surface cracks)
Without these bolts no alignment shop will do anything here and the toe I can adjust myself.

https://performanceparts.ford.com/part/M-3B236-A

Caster and Camber Alignment ECCENTRIC Bolt Kit | S197 Mustang Forum - S197Forum.com https://share.google/fmsxm6rfYkLFrApFc

I learned something new today....

 

[brasil]

When I see this picture, I noticed that there are long holes at the hydro bushing. Does that means that you have to go to an alignment shop when you change the arms? Caster is changed?

No need to visit an alignment shop . The LCA is not adjustable . Plug and play ..
Only where the LCA joins the strut there is a possibilidade that you can move the two parts against each other s little bit . But in my opinion that doesn‘t create any problems

 

[GriffX]

I would recommend an alignment check!

The more I think about it, I agree. It depends on the precision of the manufacturing process, if the bushing and joint is exactly on the same position as from the Ford factory. If not you get changes in toe/camber/caster.

 

[Dino Dino Bambino]

I'd definitely get the front wheel alignment checked whenever new control arms or new control arm bushings are installed because the camber, caster, and toe can change slightly if the previous alignment was performed on old bushings.
The Ford Performance eccentric bolts are very useful if you need a wider range of camber/caster adjustment.

 

[Midlife Crises]

Long ago I noticed a few round hole mounting points on the front end of my 2010 have a oval pattern stamped into the steel around the hole. I assumed it is a guid for using a die grinder to slot the hole so the eccentric bolts can be used.

 

[Kev555]

Dont over think it, just replace them with something quality and move on. To me it looks like a substandard wishbone or the ball joint seized putting extra stress on the ball joint housing. As suggested get the alignment checked after fitting new control arm. I would do both sides from experience if they are of the same age.

 

[GriffX]

The Ford Performance eccentric bolts are very useful if you need a wider range of camber/caster adjustment.

Sorry for the question, I'm afraid I have brainfog, you grind the lower hole in the strut to a long shape and the eccentric washer pushes against the border of the strut for adjustment?

 

[GriffX]

Long ago I noticed a few round hole mounting points on the front end of my 2010 have a oval pattern stamped into the steel around the hole. I assumed it is a guid for using a die grinder to slot the holed so the eccentric bolts can be used.

That's what I think also.

 

[metrolink]

Thanks for the help, guys. I went ahead and got the GT500 parts for both arms, which arrived tonight. The tie rod bushing was torn, too, so I'm going to replace both and then get an alignment done.