Technical Something fell off my 2017 4x4 Panda Cross - Can you identify?

[radiocode]

Hi everyone!

It is a while since I have been on here but something has stumped me. Can anyone identify where this stud came from? It fell of my 2017 Panda Cross and despite having a good look and prod about underneath and around the front suspension I cannot work out where it fell from.

The stud is M10, length 60mm with a 8mm deep nut and a 6mm locknut. There is a flat area at one end that a 9mm open-ended spanner fits perfectly. It is not oily or rusty and there is no sign of threadlock or copper grease.

The car had a metallic clunking sound for about 100 miles prior to this when we went over ruts or bumps in the road, then there was a "ping" sound and the clunking stopped immediately. We were only doing 30mph at the time, so doubled back and picked the stud up. It was the only car part we could find on the road.

Whatever it is had been knocking against something in the right front quarter of the car (Driver's side - seemed to come from the footwell/wheel area), and after it dropped off the clunking stopped. The car drives no differently now as it did before.

I have checked the exhaust, front suspension, rear propshaft bearing support and pretty well everywhere I can get to using a jack and axle stands. nothing seem to be loose or misbehaving.

Given that it is M10 with a nut and locknut, I can only surmise that it screwed into a casting or the chassis and then something attached to it that Fiat didn't want to fall off (perhaps they should have used threadlock!).

Can anyone shed light on this mysterious part?

Thanks! Lee

 

[portland_bill]

Doesn't look like anything I'd expect to see on the car. From your pics, it does not look broken, or particularly damaged, suggesting it fell out, not under pressure. If it was holding something, and became loose, I'd expect damage as whatever it was holding was chaffing at it. I can't think of anything requiring a locknut.

I wonder if it is something you ran over, and it got caught, either in very chunky tyres, inside a spring, or similar, and took a while to dislodge again.

Meanwhile, just check every part, at all its fixing points. You'll either find a hole, or nothing missing.

 

[chris3234]

Definitely does not look like it's been fitted to the car in that condition

 

[varesecrazy]

Hi

Had any work done lately??

I am wondering if its a Garages ' home made tool'..

The 9mm flat is odd.. most things commercial will be 8mm so you are under the root of the thread (8.5mm)

 

[timmycm850]

Fiat normally use nuts with nylon inserts, i don't remember anything with a second locknut. I suspect it was thrown up by a tyre and sat on the suspension arm till it fell off. Do check your car thoroughly to be sure.

 

[radiocode]

Doesn't look like anything I'd expect to see on the car. From your pics, it does not look broken, or particularly damaged, suggesting it fell out, not under pressure. If it was holding something, and became loose, I'd expect damage as whatever it was holding was chaffing at it. I can't think of anything requiring a locknut.

I wonder if it is something you ran over, and it got caught, either in very chunky tyres, inside a spring, or similar, and took a while to dislodge again.

Meanwhile, just check every part, at all its fixing points. You'll either find a hole, or nothing missing.

I agree. Every other stud on the car that screws into a casting (the turbo cover for instance) has a torx end on it, so having the flat on the end isn't consistent. The only locknuts on a Fiat tend to be on the handbrake cable if I recall correctly, and as timmycm850 said, they prefer nylock-type nuts for engine mounts and the like.

I have changed the disks and pads on the front recently but did not need to fabricate anything special for that job and there certainly wasn't anything knocking around then. Prior to that it has had the usual services by the dealer (56k miles). The noise appeared overnight, and disappeared just as quickly so it could be that I picked up the stud from the road and its been rattling around on the engine protector or a front strut.

The car is due its MOT this month, so I'll mention it then. I jacked up the front of the car today, removed the engine protector and had a really good look and probe around underneath and gave the wheels a good tug and there's nothing that seems amiss. The engine protector is in the conservatory for painting tomorrow as tin worm has been doing its best to eat it.

Once the protector is painted, I'll jack the car up again and have another look before I refit it.

Hi

Had any work done lately??

I am wondering if its a Garages ' home made tool'..

The 9mm flat is odd.. most things commercial will be 8mm so you are under the root of the thread (8.5mm)

After you said about the root of the thread, I double checked and the stud is M12x1.75, not M10, so the 9mm flat make more sense.

The nuts were done up tight with 35mm of thread exposed.

 

[The Panda Nut]

It is unfamiliar to me. Cant think of anything and suspect its as suggested above. It looks like part of a tool set like a puller. Wrong colour for a car part.

 

[Pugglt Auld Jock]

It's the locknut that's puzzling me. Can't think of anything I've worked on for quite some time that used a locking nut setup like this. As has been said above nylocks are common and even on "hot" parts, like exhaust manifolds, where nylock would melt it's usual to find the type which have "deformed" threads to achieve locking. Those flats also look unusual don't they? Not the sort of thing a manufacturer would make a standard fit, much more the sort of thing I'd file up to allow installation but personally I'd prefer to lock two nuts together to drive it home but then I'd be removing the locking nut after the stud was secure. All very weird. I hope you do find the answer as I'd love to know.

 

[Pugglt Auld Jock]

A final wee thought on this. Do you notice the lock nut is considerably "thinner" than the one beneath it? This is quite common to "dedicated" locknuts so I'm thinking this stud and it's nut arrangement is no coincidence. However I still can't bring to mind where it might have been installed. I suppose another possibility is that the stud and big nut might have been holding something like a manifold in place with a heat shield being held in place by the thinner nut? - like the heat shield on the Panda down pipe/manicat - but then you'd expect to see a bit of fractured heat shield (or whatever) still trapped under the wee nut? It's a mystery folks!