Technical Rear axle rust

[Pugglt Auld Jock]

I know I'm a bit late mentioning this but a very old "trick" with tight fixings is to try tightening them fractionally before trying to loosen them. You only need to get it to just move and no more which will often "break" the hold of corrosion on threads. A situation like this, where the bolt is installed from inside the car with the thread projecting into the wheel arch, so you could reasonably expect the corrosion to be on the end of the thread, might respond well. Of course a good attack with the wire brush and liberal dose of your favourite releasing oil _ Plus Gas for me too! - is pretty much mandatory. Once the bolt starts to turn (if you're so lucky) don't just "unwind" it all in one go. Work it back and forwards frequently with more squirts of release oil as you go.

 

[Ralf S.]

I have those extractors and that’s what I was planning to use but: the bolt sheared in the threads (deep) so no chance of extracting from inside the car & as you can understand I’m a bit nervous of drilling inside the car
As for the wheel arch end I can see the end of the bolt inside the nut … do you think it’s going to be possible to remove it from the wheel arch?

I can gather my bits now …was thinking of plus gas? Would I get that captive nut off?
I needed to remove the rear quarter panel properly and obviously I had to remove the seatbelt nut… apparently it’s common for them to shear also when I do finally remove it I need to find a replacement bolt too ugh! (Fiat aka fix it again tony)

If the broken bolt is deep in the hole, then you can try drilling it from inside the car. It's just noisier but all it is, is a captive nut on the other side of a sheet of metal, with a rusted bolt broken off in it. There's nothing around there to break, if it's the nearside (left). If it's the offside, then just don't put a blow-torch on it, that's all.. since the fuel filler pipe is behind there too.

A normal drill bit (not a reverse one) on a normal drill (not set to Reverse) will tend to turn the screw clockwise as it drills. That may break the corrosion and screw it "in" further.. which is what you want, since it would then screw through the captive nut and fall out the back of the nut, into the wheel-arch.

Doing it the traditional way, with a reverse drill bit and a reversing drill will try to screw the bolt "out" (i.e. the same as you would when unbolting it). If the threads are corroded then you will be screwing the bolt "out" against the resistance of the rust/crud on the threads... which was stuck strongly enough to shear the bolt. So, I would try to screw the bolt "in" (into the wheel arch) rather than "out" (into the car)... the threads closest to the inside the car will be cleaner and pass "out" through the nut more easily than the expose/rusty threads will pass "in".

Once/if you get enough of the bolt shank poking into the wheel arch then you might be able to get a stud extractor socket onto it with enough purchase to turn it (but remember to turn it anti-clockwise, since you're trying to screw it towards you (viewed from inside the wheel-arch).

If the broken off shank is recessed, inside the car, you can flood the recess with Plusgas etc. and let it soak in. There's a chance that it will penetrate at least some way through the screw thread /rust to the wheel-arch side before you start trying to unscrew it.

Always buy new appropriate sized drill bits for drilling screws.. about 2 or 3 each of a couple of sizes. The extra "cut" you get with new drills is worth the few quids they cost.


Ralf S.

 

[Baglady1990]

If the broken bolt is deep in the hole, then you can try drilling it from inside the car. It's just noisier but all it is, is a captive nut on the other side of a sheet of metal, with a rusted bolt broken off in it. There's nothing around there to break, if it's the nearside (left). If it's the offside, then just don't put a blow-torch on it, that's all.. since the fuel filler pipe is behind there too.

A normal drill bit (not a reverse one) on a normal drill (not set to Reverse) will tend to turn the screw clockwise as it drills. That may break the corrosion and screw it "in" further.. which is what you want, since it would then screw through the captive nut and fall out the back of the nut, into the wheel-arch.

Doing it the traditional way, with a reverse drill bit and a reversing drill will try to screw the bolt "out" (i.e. the same as you would when unbolting it). If the threads are corroded then you will be screwing the bolt "out" against the resistance of the rust/crud on the threads... which was stuck strongly enough to shear the bolt. So, I would try to screw the bolt "in" (into the wheel arch) rather than "out" (into the car)... the threads closest to the inside the car will be cleaner and pass "out" through the nut more easily than the expose/rusty threads will pass "in".

Once/if you get enough of the bolt shank poking into the wheel arch then you might be able to get a stud extractor socket onto it with enough purchase to turn it (but remember to turn it anti-clockwise, since you're trying to screw it towards you (viewed from inside the wheel-arch).

If the broken off shank is recessed, inside the car, you can flood the recess with Plusgas etc. and let it soak in. There's a chance that it will penetrate at least some way through the screw thread /rust to the wheel-arch side before you start trying to unscrew it.

Always buy new appropriate sized drill bits for drilling screws.. about 2 or 3 each of a couple of sizes. The extra "cut" you get with new drills is worth the few quids they cost.


Ralf S.

Seeing as I’m knackered from taking my headliner out dying it black and just finished re installing it I’ll have to go back and re read all the advice I’m going to order the plus gas and I do have special bits that go on the drill that grab once drilled in… think I have to do a pilot hole first…. And I’ll go from there! After I’ve removed my back seats of course!!
I’ve been thinking I’m not going to have much success with a welded on captive nut unless the nut removers I have will shift it .. but I’m a bit doubtful and may do damage to the body?!

Also yes it’s drivers side … so fuel that side so I’m not chancing heat anyway no rush I’ve got most of summer to tackle but I’m no way looking forward to it!!

 

[John202020]

Seeing as I’m knackered from taking my headliner out dying it black and just finished re installing it I’ll have to go back and re read all the advice I’m going to order the plus gas and I do have special bits that go on the drill that grab once drilled in… think I have to do a pilot hole first…. And I’ll go from there! After I’ve removed my back seats of course!!
I’ve been thinking I’m not going to have much success with a welded on captive nut unless the nut removers I have will shift it .. but I’m a bit doubtful and may do damage to the body?!

Also yes it’s drivers side … so fuel that side so I’m not chancing heat anyway no rush I’ve got most of summer to tackle but I’m no way looking forward to it!!

Don't forget the free £10 from Halfords if you subscribe that's a few cans of plus gas?

 

[TrevC]

Re. penetrative oil, I watch a few YouTube car fixing channels, and a couple of them have been using stuff called Bulldog BDX, which they have rated highly.

 

[Smeagol]

I don't recommend using any kind of paint for chassis protection on a car in regular use in the UK climate. Moisture will inevitably penetrate the paint layer, and corrosion under the paint will soon see it flaking off.

Any of the proprietary self-healing wax-based underbody protections will work much better than paint. Checking the condition of the protection, and topping up or cleaning and reapplying as necessary should be done regularly, preferably annually before the start of the winter.

That one, you’ll never get all of it from the nooks/crannies. Film every time and reapply periodically. I prefer ACF50, it’s thin but also neutralised the rust some

 

[RedAbarthMTA]

I have always found that XCP1 runs rings around any other penetrating oil. It may or may not mean anything but the AA have gone over to it. I find it excellent stuff, costs a bit more but it works

 

[Smeagol]

Had no chance removing mine when accessing the blue and me ( the first time it went wrong), the bolts are hardened for the seatbelt mount ( make sure you use a hardened one, they’re marked on the bolt head) or it won’t hold in an accident.
Snap on extractor sheared. Ended up drilling the old stub out then tapping it out.
The bolts fitted are high tensile flanged 8mm bolts. The tap- 8mm.

 

[Temeraire]

I'm just going through the infamous sheered off seat belt bolt saga. I was trying to get to the Blue & Me module (anyone know a good place
to get it repaired?). I'm shocked how easily the bolt snapped. I used very little pressure at all.

I haven't yet come up with a plan for removing the remaining part of the bolt so reading this thread with interest.

 

[John202020]

I'm just going through the infamous sheered off seat belt bolt saga. I was trying to get to the Blue & Me module (anyone know a good place
to get it repaired?). I'm shocked how easily the bolt snapped. I used very little pressure at all.

I haven't yet come up with a plan for removing the remaining part of the bolt so reading this thread with interest.

See how much of the bolt sticks out under the wing if there's enough to grip with mole grips, drill out the bolt to about 6.5mm with the aid of release oil try and wind out the bolt from under the wing ( so it comes out under the wing ) ?

I think Typecastboy's advice is to put a cut in the trim rather than remove the panel think he said you can't see it with the seat in place but could be wrong

 

[Smeagol]

I'm just going through the infamous sheered off seat belt bolt saga. I was trying to get to the Blue & Me module (anyone know a good place
to get it repaired?). I'm shocked how easily the bolt snapped. I used very little pressure at all.

I haven't yet come up with a plan for removing the remaining part of the bolt so reading this thread with interest.

Probably wouldn’t bother getting it repaired, proxi-align it out of the system, take the plug off it and change the radio. For the price they’re asking for a second hand one you can get a single din radio that’ll do what it does better.
Drill the seatbelt bolt and tap it to 8mm

 

[A3jeroen]

Drill the seatbelt bolt and tap it to 8mm

So this 8mm bolt is the first thing to break in case of an accident?
Surely nobody will take that chance on someone else's life?

gr J

 

[Smeagol]

Well it’s an 8mm hardened bolt, I’d worry fitting the wrong type, but if it’s like for like you’d struggle breaking it. Probably break every bone in your body first.
(It’s 8mm currently)

 

[Danoid]

I’m likely to do this in the next couple of months, I will be back here once I’ve done it with pictures. I hate it when people never get back when they say they’ll do something then I end up thinking “RIP”

Hello, okay it's been more than a few months...

I've recently just somewhat finished this, just needs the paint to cure now for the next 2 weeks

So I started with this flaklyness

I wirebrushed this off, but still kept a rusty finish rather than back to bare metal as the paint I used likes to be painted on rust



Now here is where I checked everything for any cracks etc, but all solid metal

So off I proceed with using Hammerite Kurust (bound to be many more better products, but I just went with easily accessble items)


I then left it 3 hours and end result looking good



I then finished the job off with Rustoleum Combi Color (Satin), I was debating whether to use a number of different products but after seeing people paint their cars and chassis' with this stuff, I thought why not and again easily accessible. I didn't use a thinner as I brushed it and seemed good consistency anyway.

The only problem is due to the temperature it'll take at least 2 weeks to cure, but thankfully we don't need to use the 500. This product works best on rust which is great, but if I wanted it to look smooth i'd be looking at ages doing it by hand and most likely better off by the car and once it's off you might aswell buy a new one anyway haha


I doubt it'll look much different in two weeks, but if it does i'll post some more pictures and if I remember, i'll get some pictures in about a years time after next winter

Cheers

 

[Ralf S.]

That's more or less what the Younger Mrs S's Rasputin looked like. I only had regular Hammerite to apply to the de-scabbed and rust-treated surface but otherwise I did that same job.

I would say that once the surface is that pitted, even it you soak it in the rust killer and are generous with the follow-up paint job, the metal will continue to rust under the surface. I think most of the de-rusting agents/converters only really treat the top 0.5mm of rust.. they don't really penetrate to much depth, so the preparation and flakey rust/paint removal is important.

The danger with painting over the surface is that it looks okay for a while but eventually the paint hides the spread of the tin-worm underneath, so I would advise re-visiting it when the weather is warmer and applying another light treatment of the paint.

My old dad invented a formula of rust-proofer "pudding" which involved mixing waxoyl, diesel and old gear oil, that could be brushed on over any surface, and being quite fluid, it penetrated better and lasted longer than just waxoyl.

These days there are similar concept products; most recently I've used Lanoguard (www.lanoguard.co.uk) which seems to be made from sheep **** and wool oil... but it sprays on, doesn't stink of sheep **** for toooo long, and semi-dries to a waxy finish. I bough some for my 500X and it seems rather splendid stuff.. so I'm going to use the left-overs on the beam on the 500..


Ralf S.

 

[jrkitching]

The danger with painting over the surface is that it looks okay for a while but eventually the paint hides the spread of the tin-worm underneath

I'd agree. Chassis components are best coated with a self healing, non-hardening, oil-based material. There are plenty to choose from, with a range of prices and reputations.

 

[Danoid]

Been over a year and just looked, few spots of brown are seen, but that’s probably more me missing bits when I used rust converter and rustoleum

I’m happy with how it is so far

 

[Baglady1990]

View attachment 439661

View attachment 439662

Been over a year and just looked, few spots of brown are seen, but that’s probably more me missing bits when I used rust converter and rustoleum

I’m happy with how it is so far

I do mine every spring with waxoyl

 

[steveras57]

I'm with Jock on this one - I wasn't getting under there to check 'em out! If I did I'd need to call the wife to drag me out and help me get up again!!! Quite honestly I have no idea what they're made of - I'm just going by the colour. If they're just part of the bump stops I'll assume there's no problem.

Gotta be some compensation for living on the arse-end of the planet - but remember the spiders!

Theres no up or down in space !! you could well be at the top!!!!! imagine ET comes billions of miles and ends up in OZ!!! phone home with a hangover!!!

 

[GettinBetter]

Nothing like a nice hard skin covering to trap moisture, and provide a nice rust incubator.

I just spray thinned out engine oil over everything underside.

• The thinners evaporates, and the oil and dries out slightly.
• After 3 to 6 months the first coat has collected a layer of fine dust from the road.
• I then do it again, over the dust, this soaks into the dust, and provides a layer that any bigger stones bounce off.
• The saturated oily dust is the perfect rust inhibitor.
• Every year, I do it again.
• If you have to do any work on it, all the bolts are easy to undo.
• Been doing it for over 30 years.