Failed Bolt - Suspension Arm

[stickshifter]

Thanks - in answer to your questions:

1) Are you running larger tires or stock size?
Stock tires
(2) Are you running a suspension lift, or stock height?
No - stock height
(3) Have you been cycling the suspension off-road?
Nothing remotely extreme other than Edinburgh potholes yet

Took delivery early last month so it’s not one of the early production models. Been driving well within limits while running in so nothing out of the ordinary/expected done.

Hopefully it’s just a defective bolt rather than a wider problem.

Yeah - the defective-bolt explanation seems like the most likely. Occam's Razor.

 

[Rab]

Looks like a bolt failure originating in the square corner of the washer locating keyway. Manufacturing defect.

 

[AWo]

If someone wants to dive into it...all about bolted joints and their failure reasons...the standard reading on this topic.

John H. Bickford -

An Introduction to the Design and Behavior of Bolted Joints​

Amazon.de

AWo

 

[Clark Kent]

There's some bruising on the flats of the nut in @pete54's 2nd pic. I wonder if someone has put a rattle gun on it and sheared the bolt inside the nut. I suspect torquing from the bolt head with the nut still at final installation torque could also shear the bolt. The keyway will be a stress point.

That joint is eccentric to correct tracking issues. The eccentric washer under the bolt head is part of the bolt. The eccentric washer under the nut is keyed to the bolt. Loosen the nut (important!) then rotate the bolt and the radius arm will shift inside the axle bracket. I can't get a brand from the bolt head markings but they're grade 10.9 and perhaps APO or AP0 (AP zero). The bolts at the front of the radius arms are marked 10.9 and KX2. Google says KX2 could be KAMAX Holding GmbH & Co. KG. They produce specialty fasteners including eccentric suspension bolts.

 

[Sela Green]

Take a good look at the initial picture. That bolt has been compromised for a while. Good catch though, much better than coming apart at high speed.

 

[parb]

That bolt looks like it has a manufacturing defect in the metal.

 

[Clark Kent]

There's no hiding the tool damage on the nut and the bolt keyway has been damaged by the washer. This joint has had maintenance after assembly.
But what really matters is that it fell apart while parked on the driveway and @pete54 spotted it. How lucky was that!

 

[Tazzieman]

As long as we don't have to add this specialised bolt to our spares kit!

 

[Tazzieman]

btw I can't see a witness mark on that bolt?
Mine has them, as it should.

 

[Clark Kent]

btw I can't see a witness mark on that bolt?
Mine has them, as it should.

Got a pic of those marks? The pics in my post above are my own vehicle. I'm not seeing witness marks there either.

 

[Tazzieman]

Got a pic of those marks? The pics in my post above are my own vehicle. I'm not seeing witness marks there either.

 

[Clark Kent]

View attachment 7840743

Gotcha. The paint pen. I have those. You had me looking for marks from a centre punch. Cheers!

 

[Tazzieman]

Gotcha. The paint pen. I have those. You had me looking for marks from a centre punch. Cheers!

The OP seems to have Silent Witness marks

 

[pete54]

The OP seems to have Silent Witness marks

There were check marks on mine but failed to take a photo of them and left the offending pieces with the dealer.

 

[David van Breda]

This is just not good enough Ineos!

 

[parb]

There's no hiding the tool damage on the nut and the bolt keyway has been damaged by the washer. This joint has had maintenance after assembly.
But what really matters is that it fell apart while parked on the driveway and @pete54 spotted it. How lucky was that!

Got to be some amazing force put down on that bolt if its due to a tool creating the damage. Isn't that bolt class the ISO equivalent of an SAE grade 8 bolt?

...and even crazier that it came out while parking or parked! what a luck, I had a similar defect from metal fatigue on an offroad vehicle, but it broke the control arm (a 3/4" part) under heavy stress while climbing a mountain. i didn't enjoy that experience a bit and i travelled at low speed. I can't image that happening while going fast...

 

[stickshifter]

I can't image that happening while going fast...

Potentially catastrophic - for the driver, the other occupants, other folk on the highway, and for the roll-out of the Grenadier in North America.

 

[David van Breda]

I'm no prophet of doom but Ineos better get a grip on the Grenadier before they find out the unforgiving nature of this market in the 21st century!

 

[Trialmaster]

I'm no prophet of doom but Ineos better get a grip on the Grenadier before they find out the unforgiving nature of this market in the 21st century!

This Forum will kill the Grenadier. I don't disagree this is a major problem. However, reading all these negatives doesn't bode well for the Ineos on this Forum.

 

[anand]

I'm no prophet of doom but Ineos better get a grip on the Grenadier before they find out the unforgiving nature of this market in the 21st century!

Not sure how many other ways to say that this bolt was a known problem in earlier productions and has been updated/fixed; and while this is unfortunate to see happen, appears to be the only one from the nearly 5000 people on this site