[Closed] Stripped a thread on the car...

Is my car buggier than this forum?

Dunno, what’s the forum issue?

Stripped subframe bolt - limp a few miles to the garage maybe, loaded up on holiday no chance.

Pretty sure setting fire to it won't help either way and may be illegal or at least really quite disproportionate.

So, not ideal but probably take it to a garage to fix somehow. The problem is, we’re due to go away on holiday tomorrow. So, do I drive it, or set fire to it and go to Motorpoint tomorrow morning (in the other car)?

Surely you are not actually seriously considering taking a car on holiday with your family in it where the subframe is only 3/4 bolted on?

Any quick fix options like passing a longer bolt straight through? (ie can you get to the other end of the threaded hole and is it open?)

Surely you are not actually seriously considering taking a car on holiday with your family in it where the subframe is only 3/4 bolted on?

It's not like it's actually held on with those bolts - the weight of the car is sitting on it. The bolts just apply enough friction to stop it moving around.

Any quick fix options like passing a longer bolt straight through? (ie can you get to the other end of the threaded hole and is it open?)

99% sure it goes into the chassis, so I don't think so.

It was an M12 bolt, and there's a bit of thread left. I wonder if I can get hold of a 1/2 inch bolt and try that?

Or I could just glue it in, on the basis that I am going to set fire to the car when I get back from holiday anyway.

Drill and tap either side of the original hole?

Got any aroldite😂

See if a local shops can helicoil it.

Ps wtf you doing with the frame down a day before you go away.

It was an M12 bolt, and there’s a bit of thread left. I wonder if I can get hold of a 1/2 inch bolt and try that?

If you get an 1/2" bolt stuck in a blind M12 hole not actually doing anything useful how much is it going to cost to fix?

It’s not like it’s actually held on with those bolts – the weight of the car is sitting on it. The bolts just apply enough friction to stop it moving around.

yeah - you are probably right the manufacturer decided to add the cost of a spare bolt, and the time taken during assembly to fix the bolt for precisely this level of redundancy. You'll be fine. So long as you don't go over any potholes or have a small accident...

M12 Threaded insert, assuming there is enough material around it to drill it out.

I have some in my workshop in North Yorkshire....

Ps wtf you doing with the frame down a day before you go away.

Long story but the subframe was never properly aligned after I dropped it last time (and asked the garage to align it), plus the bolts were old and a little bit bent so I got some more. I didn't expect this to happen, tbh.

you are probably right the manufacturer decided to add the cost of a spare bolt, and the time taken during assembly to fix the bolt for precisely this level of redundancy.

You don't think manufacturers put redundancy into their designs? I'm pretty sure they do.

I have ragged the car around a few roundabouts at far higher load and speed than I would do with family on board so it's clearly not going to disintegrate going over a pothole...

I think I would have to remove the entire thing to get a helicoil in there. Now where's my lighter?

Can you put threaded rod in and then weld it (top or bottom) and then put a nut on the bottom .or drill and tap the next biggest size bolt.Or just weld subframe to chassis (if the car is an old shiter)

I can't weld.

Probably just needs a run through with a suitable tap to sort the threads out and a new bolt or bodge it by wrapping the bolt thread with copper wire (standard multi strand 3 pin cable) as it binds inside the captive bolt surprisingly well (old rally car bodge) and for extra measure drill the bolt head and use wire to tie it securely.

Take the nut off, put 3 washers on over the stripped bit, replace nut and tighten.

It's not fine.

5.3.3. Suspension arms, rods, struts, sub-frames, anti-roll bars etc.
Some vehicles use thin gauge steel pressings for some highly stressed suspension components. Many of these parts have hollow ‘box sections’ or up-facing areas that can collect road dirt, salt or other chemicals that can cause severe local corrosion.

You should pay special attention to these components.

You can find guidance on assessing corrosion in Appendix A.

It may be easier to inspect suspension components with the wheels jacked for the checks in Section 5.3.4. You do not need to jack the rear wheels of vehicles with a DGW more than 5,000kg.

Defect Category
(a) A suspension component:

(i) insecurely attached to chassis or axle
(ii) missing, likely to become detached or directional stability impaired

Major
Dangerous
(b) A suspension component:

(i) excessively damaged or corroded
(ii) fractured or likely to fail

Major
Dangerous
(a) A suspension component:

(i) with an unsafe modification
(ii) modified so that the suspension is inoperative or likely to foul other components

Major
Dangerous

https://www.gov.uk/guidance/mot-inspection-manual-for-private-passenger-and-light-commercial-vehicles/5-axles-wheels-tyres-and-suspension#section-5-3-3

for goodness sake do not even think of driving it. Dangerous . illegal and your insurance will not be valid

It’s not like it’s actually held on with those bolts – the weight of the car is sitting on it. The bolts just apply enough friction to stop it moving around.

Until you stress it hard ie bump, emergency stop, evasive action etc

Don't you have s brand new electric car take that

Electric cars are the future.

The bolt you used might be slightly undersized. Have you got the original?

on the basis that I am going to set fire to the car when I get back from holiday anyway.

Why are you straightening the subframe on a car you are replacing soon..seems a lot of effort for one journey

The bolt you used might be slightly undersized. Have you got the original?

That's a scary thought, that the other bolts could be insecure! Molgrips, have you confirmed the thread pitch is the same on the replacement bolts, and not fine thread or vice versa?

This really is pretty simple. Take out the legalities and the insurance implications and just go back to direct consequences of your assessment being wrong...

Are you prepared to chance killing one or more people on the basis that you (who are not an automotive engineer iirc) can safely and accurately assess the impact of having one of the four attachment points for a major structural component of the car in a defective state?

Maybe sounds harsh but that is the call that you're proposing to make.

What you need is a hire car or a time machine.

You my friend are in a whole world of pain with this.

Happened with my Transit - the retained nut buried deep in an inaccessible box section broke free and rotated. The only way to access it was a lot of measuring followed by more measuring then a 2" holesaw on an extension arbour to drill through the passenger footwell then a panel below that. Finally then being able to cut the head of the bolt off from below and knock it up with the remains of the captive nut. Replaced with a nylock and new bolt

Hire a car for the hols.

Why are you straightening the subframe

It's more of an adjustment rather than straightening I'd imagine if he's do it Ng it on the drive.

Most vw(if not many cars ) if you get subframe alignment wrong the gear box will knock against it under power. It's an awesome sound.

How did the old bolts get bent if they aren’t under lateral load.
I wouldn’t be driving that. Drop the subbie properly and work out how to repair it.
Wanging an oversize imperial bolt up it is not a fix.

I can’t weld.

You are going to need a bigger bolt!

But what extra stress will that or a helicopter put on parts not tested for them? If it was that weak it could have broken in pot hole so look at the positive that you discovered a potentially disastrous issue.

Is hiring a car an option for the holiday?

Gaffer tape?
Cable tie?
What could go wrong... Where is your sense of adventure...

I had a sinking feeling Moly that this would be your Passat (it is a Passat isn’t it?) when I saw the thread title. It’s bad luck but I’d be hiring. No way would I be taking my family in it, or putting other people at risk, even if it is possibly only a marginal one.

Back to the bolt - have you tried running a tap through it, the chassis that is? That would always be my first port of call for this type of thing.

sounds like the car is getting a bit past it, so would it be silly to suggest doubling down on your holiday and hiring a Mustang from your local Enterprise for the week, or even nice big mondeo?

week in a broken shtbox or a week in a nice new car with A/C and nothing to worry about.

Lol You’ll ignite the flames of worry and panic on this forum.

Drive it to a garage and get a helicoil fitted.
It’s really no big shake.

I’d run a tap through it first then try it again , but if you can’t do it yourself just drive it to a garage
It won’t fall to bits on the way.

@tjagain

I actually wonder how you get out the door sometimes.
You must panic about every single thing.

How did the old bolts get bent if they aren’t under lateral load.

I did read that and think......is that normal.....

I've pulled a few and never had *bent bolts*...... Even on a car that had a front end passenger wheel impact that bent the chassis...... Sub frame was golden as were it's bolts.

What is more common than stripping these threads- and given that stripping is interchangable with rounding the head by most users on there it's probably worth mentioning...... is that the captive nut detatches from the metal work and spins freely.....in which case helicoiling it wouldnt work

I have a Karate Jinx
I have a Cycling Jinx
I have a Car Jinx

As long as I keep a vague eye on the disasters that befall these people I manage to avoid various beatings, crashes and mechanical failures.

Moly old fruit, you are my Car Jinx.

Keep up the good work!

is it definitely the chassis thread that's damaged and not the bolt thread?

Had similar happen with a roll bar thread on my van at weekend. In that case it was deffo the chassis - the bolt was unmarked - seems like the bolts are harder than the welded nuts - which is daft - would be so much easier if it was the other way round. In my case I stopped sharpish and a tap sorted it no problem.

It’s not like it’s actually held on with those bolts – the weight of the car is sitting on it. The bolts just apply enough friction to stop it moving around.

Yeah, no. The subframe is located and braced against the body. The bolts help locate it, and the clamping force helps hold it steady.

I've driven some daft cars in various states of disrepair but I wouldn't drive one without the subby properly held on.

Take it to a garage, they'll either helicoil it, or cut a hole in the frame rail, and weld a captive nut from the inside.

This is pretty common in s14 200sx s, and it's a ballache.

The longer this car is on the road, the greater the danger to you and, literally, everyone else.

Drive fast. Reduce the time this vehicle is on public roads by driving as fast as it will go. Then a bit faster.

Be sure to post links to dash cam videos.

Well you are right of course, once my emotions have settled down.

Basically I have finally used up my reserves of emotional commitment to that car. **** the bastard thing. I'm in Trade Centre Wales buying one of the two cars they had with a towbar. They were the same price - a relatively recent Kia Sportage and a 62 Mercedes C class.

We might not even be late for our holiday at this rate.

I'll get the Passat fixed when we get back.

I may not keep this Merc for long, maybe until it need tyres..

Brads - I will not get in shagged cars. Far too dangerous.

I won't drive old bangers and even when i get a hire car I check it properly - tyres etc.

Car with a missing subframe bolt is unroadworthy as per the quote above my post and thus insurance is void

You've sorted out a new car! Excellent decision, well done. The need for a tow bar definitely complicates getting a hire car, hopefully the new car comes with a bit of a warranty for you.

Happy holidays! What on earth will you do with all your free time now you're not fixing the Passat every weekend? 🙂

Your assumption of the subframe being compressed against the body is only true if the top of the springs attach to the subframe. If the suspension arms attach to the subframe but the springs attach to the body (i.e. normal strut towers in the body) then the subframe is pulled AWAY from the body by the reaction force at the lower suspension arm inner bushes. I've just done a chunk of subframe bush testing at work so reasonably familiar with how they work (they have built in snubbers that operate in that direction under big vertical bump forces). Plus all the other lat / long forces from braking and cornering etc.....

Did you use new subframe bolts? If they are torque and angle then normally single use and could explain the stripping.

Replacing the old re-used ones with fresh was on of the reasons for doing it.

Brads – I will not get in shagged cars. Far too dangerous.

Not sure why you got singled out for that criticism TJ, you weren't the first to point out what a bad idea it was! All well that ends well anyway. Apart from the fact be bought a nearly decade old Merc rather than a young Kia. 😁 I wonder how many exotic and unusual ways there are for Munich taxi's to break down?

I'm sure it was a common issue on MK2 golfs for the captive nut to brake loose and spin. It required part of the footwell to be cut out and a load of weld added to the nut.

It's fixable but depending on the location of the nut it's a big job or an even bigger job.

Trade Centre Wales

Isn't that the gobby anti skatepark guy everyone was beeping at a few weeks back?

The tj dig was slightly tongue in cheek as he seems to be a rule follower to the extreme.
As for the insurance being null and void , that’s simply not true.

One non torqued subframe bolt does not necessarily make the car unroadworthy and that would be for a DoT engineer to decide if there was an accident involving this car.

If stopped and some X-ray vision equipped cop spotted it it would only be a 21 day ticket anyway most likely.

Even if it was deemed not safe it still wouldn’t void your insurance.
If that was the case , every car with a blown tail light or a bald tyre would be uninsured.

Just helicoil the bloody thing.
Or weld the bolt in 😂

Just helicoil the bloody thing.

I will when I get back from holiday...

Enjoy your hols Moly - sounds like you’ve earned it !!👍

I can't believe he isn't stripping it down at the campsite and welding it off the hook up supply.

#youvechanged #simplyoutrageous

I can’t believe he isn’t stripping it down at the campsite and welding it off the hook up supply.

Wait for it…….
“What welder do I need, only have a 6amp supply on the campsite though”
“I’ve bought an inverter welder, what mask should I get”
🤣🤣

Enjoy your holiday.

The bolts just apply enough friction to stop it moving around.

That made me laugh. I think you meant that the bolt USED TO apply enough friction. All bets are off with only 2 of the 4 appearing to be fully in place!

Glad you got sorted for your holidays, even if you've now had to spend all the ice cream money on a new car.

What welder do I need,

Daisy chained car batteries and a arc handle.

All bets are off with only 2 of the 4 appearing to be fully in place!

Three of four, plus the bushing brackets.

If it's a captive nut that's become detached, would a rivnut do the trick? Or would it not be strong enough?

https://jalopnik.com/this-little-wonder-is-a-rivet-and-a-nut-in-one-and-bett-1847259327

Seriously? A rivnut for a suspension component that uses a high tensile torque and angle tightened fastener?....

No no no no no no no no

Riv nuts are aluminium and low strength.

Would you mount your rear suspension links to your bottle mount on your bike......

Industrial rivnuts are also available in steel or stainless and come in bigger sizes than water bottle mounts!

The issue is these captive/retained nuts are usually buried in closed/inaccessible box sections. The only way to get to them is with a holesaw either from the side or down through the footwell then either weld in place or replace with a nylock.

I took pics of my Transit when the wishbone mounting bolt 'spun' but I deleted them as I don't want to be remained of the absolute ballache of the job.

This should be easier to sort though as from the sounds of it the ‘nut’ is still in place, it is just the thread that’s gone, so run a tap or helicoil should sort it out..

Yep. But I doubt anyone has the kit to fit an m14 steel insert at home.

V true - I can’t imagine most people would have much use for it!

Yep. But I doubt anyone has the kit to fit an m14 steel insert at home.

Guilty

Would I use it in this situation.....probably not.

Would you mount your rear suspension links to your bottle mount on your bike……

I have never had a bike fancy enough to have rear suspension...