Technical Rear subframe
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Technical Rear subframe
Looks quite heavily corroded, so the plastic didn't do much of a job. Any mention on last Mot?
OP
OP
No the only items on any of the previous mot's was tyre wear, but also coroded sump which has been replaced. done 53000 miles
There’s some sort of powder coating that flakes off and causes surface rust
The pretty much all do this
9 times out 10 this is wear it stops. They look terrible but nothing structural
A few go worse, no idea why. More salt on the roads, different batch loads of theories but in the end it makes no difference
If it’s not already too bad then you have two cheap options
Wire brush and protect with oil, grease, waxoil or similar
Or do nothing and hope for the best. Replacement part is available but time consuming to change
Personally prevention is better cure both time and cost
But if I was not keeping the car much long I would leave it to the next owner.
The pretty much all do this
9 times out 10 this is wear it stops. They look terrible but nothing structural
A few go worse, no idea why. More salt on the roads, different batch loads of theories but in the end it makes no difference
If it’s not already too bad then you have two cheap options
Wire brush and protect with oil, grease, waxoil or similar
Or do nothing and hope for the best. Replacement part is available but time consuming to change
Personally prevention is better cure both time and cost
But if I was not keeping the car much long I would leave it to the next owner.
OP
OP
New what car or subframe?
OP
OP
Thanks Koalar only bought this car recently for my Grandson who is not 17 until early next month so will be keeping it but too old now to be changeing the subframe.
17 great age to get them started on car maintenance and crawling around under the car
OP
OP
Agree with that but I don't think that is going to happen here his only interest is in driving it, times have definitely changed since I was a young un.
Subframe.
The rear beam used to be an OEM-only part, close on £1000, but aftermarket pattern beams can be had now for £150 or so, making this a cost-effective repair even if paying someone else to fit it.
The ready availability of pattern parts gives you some idea of just how common this problem is. There's no doubt that these aftermarket beams are going to save a lot of cars from being scrapped.
Some folks have gone to a lot of effort to address this issue, stripping everything down and sending the beam away to be gritblasted and hot-dip galvanised. A perhaps more pragmatic solution is to spray the contents of a waxoyl aerosol can onto the beam. If done annually, the beam you've photographed will likely see the car through the rest of its life.
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OP
OP
Yes seen them for £150, it does not seem too difficult, I have all the facilities to do this job but at 84 years of age I think I might struggle to do it now, I would like to give it a go but maybe I am dreaming. I have had a good look at the axle/subframe and it does to be still strong, it has never failed it's Mot on corrosion just tyres, last Mot 31/8/22 so I may just give it a good scrape and cleanup and protect it with something but with what?. Waxoil as has been suggested.
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Corrosion? This is what my rear drums looked like
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It's tuff up North
That subframe looks like it needs to be chiselled off with a drift (I use an old screwdriver) and a small hammer, to get all the flakes and layers of corrosion off. It'll take a while (an hour or two anyway) and also wear some safety specs and ideally a left-over Covid mask otherwise you'll be finding rust flakes up your nose, in your ears and under your dentures for weeks. 
Apart from that, it's quite satisfying, so worth the aggro'... and if you can jack both sides up onto stands, and find a big piece of cardboard to lie on, it's quite therapeutic. You can pretend you're still busy as you lie there for the entire afternoon....
Afterwards, wire-brush the surface, treat it with a rust converter product.. so it turns black/purple all over and then spray it with some waxy stuff. I recently tried some Lanoguard on my X, since it's new... but any cavity wax (e.g. https://bilthamber.com/product/dynax-s50/ ) will protect the top layer of the treated metal.
Lanoguard is colourless but stays "soft" even once dry. I found the s50 to be harder but it's a dark brown colour, so you can't use it anywhere else that's "visible"... although for the Titanic-impersonating rear beam that probably doesn't matter.
Ralf S.
Apart from that, it's quite satisfying, so worth the aggro'... and if you can jack both sides up onto stands, and find a big piece of cardboard to lie on, it's quite therapeutic. You can pretend you're still busy as you lie there for the entire afternoon....Afterwards, wire-brush the surface, treat it with a rust converter product.. so it turns black/purple all over and then spray it with some waxy stuff. I recently tried some Lanoguard on my X, since it's new... but any cavity wax (e.g. https://bilthamber.com/product/dynax-s50/ ) will protect the top layer of the treated metal.
Lanoguard is colourless but stays "soft" even once dry. I found the s50 to be harder but it's a dark brown colour, so you can't use it anywhere else that's "visible"... although for the Titanic-impersonating rear beam that probably doesn't matter.
Ralf S.
OP
OP
Thanks for your reply don't have dentures by the way got all the rest, I also have a 28' by 10' garage and also a Grandson who has reduced the internal space that makes it difficult for even my dog to get in there. So I am going to instruct him to remove his crap and then i can get this little fiat in there all the necessary tools are in there and i am going to get this Fiat's back end up in the air take the back wheels off and give it the once over to see what is required. i am of a mind to replace this subframe/axel with a shiny new one as they are quite cheap, if the axel seems to be not too badly corroded I will clean it up protect it and call it a day. Just need the energy to do it, thought my days of grovelling around under cars had long gone.That subframe looks like it needs to be chiselled off with a drift (I use an old screwdriver) and a small hammer, to get all the flakes and layers of corrosion off. It'll take a while (an hour or two anyway) and also wear some safety specs and ideally a left-over Covid mask otherwise you'll be finding rust flakes up your nose, in your ears and under your dentures for weeks.
Afterwards, wire-brush the surface, treat it with a rust converter product.. so it turns black/purple all over and then spray it with some waxy stuff. I recently tried some Lanoguard on my X, since it's new... but any cavity wax (e.g. https://bilthamber.com/product/dynax-s50/ ) will protect the top layer of the treated metal.
Lanoguard is colourless but stays "soft" even once dry. I found the s50 to be harder but it's a dark brown colour, so you can't use it anywhere else that's "visible"... although for the Titanic-impersonating rear beam that probably doesn't matter.
Ralf S.
Bodga
Member
The rear axle on my daughters 2008 500 isn’t much better, i just give it a scrape and apply some spray of anything I’ve got in the garage If I’m under there for any reason.
I do find it funny thou as I have a 1988 golf GTI in the garage that I rescued off someones drive back in 2009 that was going to the scrapyard and it still has its original rear axle
I do find it funny thou as I have a 1988 golf GTI in the garage that I rescued off someones drive back in 2009 that was going to the scrapyard and it still has its original rear axle
Piccolo Nero e Bella
Prominent member
I just find it extraordinary that any car built this side of the 70's should be so susceptible to rust, let alond full blown corrosion!
Inspection of my own car's underside suggests little problem with rust but can anyone advise if the apparent crack at the back in the attached photo is just a poor weld or a cause for concern?
As far as I can see there's nowt wrong with the weld on the outside.
Inspection of my own car's underside suggests little problem with rust but can anyone advise if the apparent crack at the back in the attached photo is just a poor weld or a cause for concern?
As far as I can see there's nowt wrong with the weld on the outside.
Give it a poke with big screwdriver too be sure, but I think it is paint flaking off, as just above it the paint looks a little bubbly.
Piccolo Nero e Bella
Prominent member
Maybe - I hope so.
Here's a blow-up of that photo;
Here's a blow-up of that photo;
