I have just been advised by my local (and trusted) garage that I need to replace my front ARB as it has corroded where the bushes meet meaning the bushes will not contact properly. My question is though should I simply replace with another VAG item or buy an uprated one? I dont really drive fast or go on track days though so I would I get the benefit of spending alot more money?

This happened to me but the new one, i think £105 with all the bits needed has been redesigned and has new type of connectors to stop the problem occuring again

I fitted the new 'S' type bushes to mine at the weekend, and it's sorted it. No more nasty creaking!

The original 'P' type bushes have a 20mm internal hole to allow for the plastic sleeve over the 19mm bar. The new 'S' bushes are designed to run without the sleeves, directly on the 19mm bar.

Is the bar actually cracked or is it just rusty because it's worn off the paint (like they all do)?

I've looked at it as it just rusted where the bushes make contact. I guess this thins the bar out and means the bushes wont grip properly. the car does feel wobbly sometime too so I guess it all related and the the arb can move around side to side.

I've looked at it as it just rusted where the bushes make contact. I guess this thins the bar out and means the bushes wont grip properly. the car does feel wobbly sometime too so I guess it all related and the the arb can move around side to side.

Common problem on the VAG cars.

The original ones have a sleeve that is prone to cracking and then it makes the bushes sit on a thinner area causing movement.

I just replaced mine with a Golf R32 one (23mm)

My old ARB is knacked.

I do have the Superpro uprated bushes for the standard ARB if anyone interested only been on car a few months and like new.

The FARB problem is common. Given that more or less everyone who complains complains about understeer, then unless you're fitting a RARB, there is no need to upgrade the front one.

I fitted the new 'S' type bushes to mine at the weekend, and it's sorted it. No more nasty creaking!

The original 'P' type bushes have a 20mm internal hole to allow for the plastic sleeve over the 19mm bar. The new 'S' bushes are designed to run without the sleeves, directly on the 19mm bar.

Is the bar actually cracked or is it just rusty because it's worn off the paint (like they all do)?

Been doing abit of thinking along those lines as I have much better things to spend £100 on at the moment (bloody holiday season!). Would it be better to run the S bushes or find some from a lowly VAG with a something like a 17mm bar and stretch them bushes over the bar nice and tight? Or I could pack the bushes out with a rubber lining of my own?

Just have the old plastic sleeve removed, clean up the rust underneath with emery cloth and fit S bushes - they only cost about £5 a pair.

Just have the old plastic sleeve removed, clean up the rust underneath with emery cloth and fit S bushes - they only cost about £5 a pair.

How does this prevent the corrosion recurring, now that the ARB coating is missing under the mounting bushes?

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How does this prevent the corrosion recurring, now that the ARB coating is missing under the mounting bushes?

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It doesn't really but it is very (very) common to have corrosion around the arb bushes as the paint always gets rubbed off there. In most cases, this does not become an issue. In the Octavia, the issue of corrosion is only a problem because the plastic sleeve becomes detached from the bar (should be bonded onto it) and starts to slide around it (the plastic on rust contact area making the horrible creaking noise). If you don't have the plastic sleeve, no creaking noise.

Both my last cars had loads of rust around the point where the arb passes through the arb bush and and neither suffered any adverse effects.

I removed the plastic sleeves on mine about two months back and added the newer type bushes and clips (total price about £10). Job took about an hour and the noise has completely gone. Not sure how long it will last but reports on this site suggest it is a perfectly good medium term solution.

Given it is an easy job and costs very little to do, I'm prepared to do this a good few times before spending big money on a new arb (parts and labour expensive as the sub frame has to be dropped to get the old one out and new one in).

Cheers,

iep

It's not an issue for me, but I'd understood the rust reduced the thickness (and I know it reduces the bending stress load as lb / degree) of the ARB.

so is there supposed to be grease between the anti roll bar mounts and the bar or not? Mine look as though they have been coated at some point but i have no problems.

I threw in a load of copper grease. Seems to have worked.

As for rust reducing thickness, I can't see it being a problem. We are only talking about a thin layer of surface rust. For the rust to reduce the diameter by even a mm you'd have to be looking at LOT worse corrosion than I was seeing on mine (bearing in mind mine lived in the north of Scotland on very salty roads before I bought it).

iep

A quick calc says that an 18mm bar has only 85% of the area, and hence torsional stiffness of a 19mm.

But if the rust is localised around the bushes (as it was on mine) then you are only talking at most 2% of the bar length being affected. So only 2% of the bar is actually 15% less stiff.

This would suggest that the overall reduction in stiffness is only 0.3%. Manufacturing tolerance will swamp that figure.

There is a an argument that the localised weakening could cause a fracture at that point but I would be surprised if the actual reduction in diameter is anywhere near 1%. Certainly, when I measured my own arb with digital calipers (after emery papering the worst of the rust off) it was less than 0.1mm different to the clean area of the bar.

Just my experience,

iep

How does this prevent the corrosion recurring, now that the ARB coating is missing under the mounting bushes?

It doesn't, but copious amounts of grease help.

I certainly didn't remove 1 mm of rust - I doubt if it was more than a few thou of surface rust rubbed off manually.

Incidentally, I used silicon grease. I was taught years ago never to use ordinary grease, spray grease, WD40 or Coppaslip on rubber bushes, as they all contain hydrocarbon based solvents (I believe in the case of WD40 and the spray greases this is Naptha) which will attack the rubber, but that silicon grease is effectively inert. May be obsolete info. with changes in product specifications and types of synthetic rubbers used, but it works for me.

But if the rust is localised around the bushes (as it was on mine) then you are only talking at most 2% of the bar length being affected. So only 2% of the bar is actually 15% less stiff.

This would suggest that the overall reduction in stiffness is only 0.3%. Manufacturing tolerance will swamp that figure.

There is a an argument that the localised weakening could cause a fracture at that point but I would be surprised if the actual reduction in diameter is anywhere near 1%. Certainly, when I measured my own arb with digital calipers (after emery papering the worst of the rust off) it was less than 0.1mm different to the clean area of the bar.

Just my experience,

iep

You might be surprised how much effect it has on roll stiffness. It can be shown (by someone who's not forgotten the maths being the empirical knowledge) that a variable thickness rod will twist more in the thin parts than the thick ones for a given applied torque, and I'll bet that the bushes cover more than 1% of the straight length of the bar (sight unseen).

The plastic sleeves have detached on my arb too.. this has caused the arb to move side to side rubbing the droplink on the side of the turbo pancake pipe .

The plastic sleeves have detached on my arb too.. this has caused the arb to move side to side rubbing the droplink on the side of the turbo pancake pipe .

You could fit jubilee clips on the ARB where the old plastic sleeves used to be. I have seen this on a number on VAG motors, The screw part of the clip is held up against the bush and thus performs the same job as the old sleeves and stops the ARB sliding.

I have also known of people replacing the old bushes for 18mm ones when the sleeves are removed to keep the bar tight and also help stop sliding.

I have also known of people replacing the old bushes for 18mm ones when the sleeves are removed to keep the bar tight and also help stop sliding.

The newer Skoda S revision bushes that run directly on the bar are 17mm

The newer Skoda S revision bushes that run directly on the bar are 17mm

That is true , stand corrected.