A warning about replacement lower wishbones

[ChrisG]

I thought I best share this, as this for me was a serious safety concern.

Some time back, I put the A8 through its MOT and got its usual list of replacements needed, which included the lower suspension wishbone arm due to a perished boot.
As you may know, you cant buy the ball joint by itself - you replace the whole arm.

As you always do, you trust the garage, who ordered a none Audi replacement, and fitted it, along with a steering trackrod end.

The garage at the time was a well known "fast attachment" garage (work it out and yes, I was an awful numpty for ever trusting them).

About 8 months later, I started getting odd problem. The ABS warning light was coming on and the steering wheel was off centre.
So I took it down to my now regular garage and asked them to look at it.
Well... what they told me, turned me sheet white.
Firstly the Trackrod had been fitted, but not tightened up at all. It was loose, and the reason the ABS warning was going off was it was unwinding itself - the wheels were not straight anymore and with a sharp shock, the front wheel could have broken loose of the steering on that side.
However they also found, the replacement wishbone was also loose. It had been fitted correctly, but it seemed whoever had fitted it, put a Nylock nut to hold the ball joint in place.
The garage repaired the trackrod and did a full laser wheel alignment on the car which stopped the ABS light and the steering wheel went back to straight.
Sadly though this nylock was a different issue entirely. The nylock was due to the wear and motion, unwinding itself, which then loosened the arm.
There didnt seem to be any way of retaining the nut tight.
The solution was a old trick we used to back when I was doing classic VW.
Double nutting. This is fitting two nuts to the thread, then cross tightening the nuts against each other locking them in place. With a little bit of thread lock too, this fixed the issue and I checked it later.

Then the next year, the garage had to do the other side for the MOT.
Same situation and the parts came in from... well ... a European motor parts company that is well known in the UK.
When it turned up, same as the other side. No locking method - just a nylock.
They fitted it and thread locked it.

Roughly 4 weeks later, after driving down the motorway to take my daughter to her riding lesson, we finished, up, pull out of the car park and drove down the country road when suddenly and without warning, there was a bang, and the car went nuts... couldnt drive or steer it properly.
Pulled in to to a carpark, got out, and found the front wheel was at a very odd angle in the wheel arch - checking it, the wishbone had fallen off.

In short, the nylock nut provided had fallen off some time back and the suspension was floating free - terrifying to think a hour before, I had been doing 70 on the motorway.
The garage was mortified, and needless to say they repaired it and made it bullet proof. However that was also a catalyst for them to cease their trade with said auto parts supplier too.

When you replace these wishbone arms, be very suspicious of arms supplied with Nylock nuts for the main ball joint.
Nylock nuts are designed to hold a bolt fast so it doesnt spin unless you provide enough leverage to make it move. Its not a fully locking item.
So when you are dealing with a major stress point on a car, nylocks are not suitable.
On older cars they used to use castle nuts with split pins, so you could tighten the item up, and then with the split pin, lock it in place... physical mechanical locking.

What worries me is twice, I could have ended up having a serious accident thanks to poorly designed replacement parts. And I am talking about the kind of accident that would do lots of damage and possible threat to life. Imagine what would have happened if that suspension arm had failed at 70... the Wheel getting smashed in to the wheel arch, followed by either spins, or even rolling the car.

Anyhow... thats the warning...