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Fitting a new Rear Anti Roll Bar on A5 Chassis


octavia5

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The A5 Chassis covers the Golf MKV, Octavia2, Audi A3 and some Seat models.

Essentially fitting a replacement RARB to an A5 chassis looks as simple as undoing 6 bolts and off the old one pops – but nothing is ever that simple is it?

Fitting a replacement may not be quite as simple as expected – depending on which RARB you choose, and in any case you will need tools you may not have and to source new VAG replacement Bolts and Nuts as they are defined as ‘One Time Use’ only.

To remove and refit a RARB you will need:

A set of Spline (Male) sockets – specifically 8mm and 6mm. Do not confuse these with the ‘T’ series of fastenings, you must use the correct Spine sockets.

16mm Ring Spanner – you cannot use a socket

A pair of Ramps, and something to lie on

Torque Wrench – for refitting.

The (Skoda) Part numbers for the replacement VAG Nuts and Bolts are:

Bolts for the Clamps x 4, P# == N 106 447 01 Cost 50p each +VAT --- Description == Socket Head Collared Bolt with inner multipoint head (M8 spline socket head) -- Tighten to 20nm + 90 degrees

Nuts for Coupling/Drop Link Screw x 2, P# == N 102 8661 10 Cost 46p each + VAT --- Description == Shouldered Hex Nut, Self Locking M10 thread with 16mm standard Hex Head -- Tighten to 45nm

Replacement Coupling/Drop Link Screw x 2, P# == WHT 000 226 Cost 79p +VAT ---Description == Socket head bolt with inner multipoint head (M6 spline socket head) M10 thread x 55mm long. Note it is not essential to replace this Screw just the nut.

Note -- the Screw which goes through the lower end of the Coupling/Drop Link is M10 thread x 55mm long, This has an internal M6 Spline and requires special tools to set the correct Torque. If you are familiar with using a Torque wrench and since the nut is self locking you may feel confident enough to simply tighten the new nut ‘by feel’ to the ‘correct torque’ using the 16mm Ring Spanner - but this is at your own risk.

As for choosing the replacement, normally stronger, bar it helps to accurately measure the size of the one on your car, as VAG offer a number of different diameter RARBs whose fitment I assume depends on the model of your car.

VAG offer:

a - 19.6mm, P# 1K0 511 409 BH (Skoda Part #s)

a - 20.7mm, P# 1K0 511 409 BE and,

a - 21.7mm, P# 1K0 511 409 BF

so you may be able to simply fit a thicker RARB from a different VAG model at a relatively lower price or even source one from a breakers or someone who has upgraded.

NOTE: The VAG RARBs are all made from Hollow Tube unlike most 3rd party bars which are solid. Therefore none of the VAG bars can offer the same amount of control a solid bar will, but the choice is there.

I have no info as to what bar is fitted to what car but Seats are known to have stiffer suspension than most so they might be worth investigating. However most people will be looking at fitting stiffer third party RARB so read on.

The bar on my PD140 measured 19.8mm with a digital micrometer so I assume it was the 19.6mm one.

After much searching of VAG forums, asking questions and searching on what 3rd party options there were available I decided to go for the ‘WHITELINE 24mm Adjustable RARB’ – this had several good reviews on VAG forums and it was the only one I could find which did not come as part of a kit of Front and Rear ARBS, at significantly higher prices.

The Whiteline bar has three holes along its mounting ‘blades’, which bolt to the Drop Links, to allow you to set at soft, medium and hard rates, even the soft is harder than the standard VAG bars. Most other bars appear to be single setting. Be sure to obtain a RARB specifically for the A5 chassis, the Mk1 Octavia and Golf MKiv bars will not fit. Search for Octavia 2 or Golf MKV fitment.

However when fitting the Whiteline ARB its mounting ends, blades, are much thicker than the standard ARB and therefore the standard VAG nuts do not fully screw onto the mounting screws thread – the screw threads stop inside the nut. Therefore I do not believe the standard VAG mounting Screws and Nuts can provide a safe mounting option – there should always be at least 2-3 screw threads protruding from the end of the nut to be sure of a good mechanical hold and as the VAG nuts are self locking they must be fully tightened throughout, and beyond, their length to provide an effective ‘self lock’.

Whiteline do not provide any mounting hardware other than the bushes to fit their bar and they expect you to provide your own mounting hardware putting the emphasis on the safe fitting on your head. In my opinion this is a major oversight on Whitelines part as I feel it is their responsibility to provide safe fittings for their products – but after contacting them several times through their dealer they refused to provide suitable mounting nuts and bolts.

After much investigation I have decided to go with M10x70mm Stainless Bolts with a washer at both ends and M10 self locking (Nylock) nuts, you could possibly use standard VAG nuts - BUT these are Galvanised and it is not a good idea to mix Stainless and Galvanised, especially on such an important part. Having fitted the bar it might be possible to use M10x65mm bolts and have sufficient thread for the nuts.

Other makes of RARBs may well have thinner mounting blades than Whitelines as I suspect theirs are so thick because they have 3 mounting holes drilled through them to provide the adjustment, bars with a single mounting hole could well be thinner and standard VAG mounting hardware used but please measure carefully as this is naturally a high stress part of the cars rear suspension.

Removal:

Note: If the threads on the bolts/screws are badly corroded it is a good idea to wire brush them and put some penetrating oil on for a couple of hours before starting

Image2-1_zps56fcc9c3.jpg

The RARB should be removed and replaced with the weight of the car on the wheels so you will need a set of ramps for the rear wheels – the higher the better, unless you have access to a proper lift – ensure the handbrake is secure and the front wheels chocked before going under the car. The offical reason VAG give for doing the job with the weight of the car on the wheels is so you do not upset the geometry of the rear suspension. Do NOT use any type of jack for this job – they are unsafe for working under the car and the weight must be on the wheels to ensure there is no stress on the old and new bars during replacement.

All work is done from the rear of the car, preferable with something to lie on – I used some old vinyl cushion flooring.

First just loosen each of the mounting bolts using the M8 Spline, to make sure they are not seized

Then loosen the Drop Link nuts by placing the 16mm Ring Spanner over the nut and the M6 spline socket into the end of the Screw – this is necessary to stop the Screw from rotating, it has a round end so you can not put a spanner on it to stop the screw from turning.

When every thing is loose, continue to remove the bolts and nuts leaving the RARB sitting on the Drop Link Screws – then carefully spread the Drop Links while supporting the bar and remove it.

Remove the Clamps which fit over the RARBs rubber mounting bushes, you will need to use a large spanner or hammer to knock them of as they will be griped tightly by the old bushes.

Replacement:

Fit the new bushes supplied with the new RARB to the bar, follow the manufacturers instructions as to whether they should be greased or not.

Fit the Clamps removed from the old RARB over the new bushes, unless your supplier provides new ones, these will be a tight fit – I had to stand on mine to push them home.

Then replacement is simply a reverse of the above.

Insert whichever Screws or Bolts you are using into the Drop Link bushes and wriggle the new RARB over them and loosely put the nuts on to stop the bar coming off.

Image3_zps0bbb92b6.jpg

Image4_zpsc6b710f8.jpg

Line up the Clamps with the mounting screw holes and insert the lower M8 Spline bolt into each side a few turns.

Insert the top bolts and tighten each bolt in turn a little at a time – do not over tighten at this stage.

Tighten the Drop Link Bolts till nearly fully tight.

Now you will need a torque wrench to tighten the M8 Spline mounting bolts to 20nm + 90 degrees.

Image5_zps4dd7fa94.jpg

The standard VAG drop link nuts should be tightened to 45nm but without some sort of Torque Spanner or special tool, you can not do this so you will have to use the M6 spline to hold the screw while tightening the nut with a ring spanner till you feel it is tight enough – this is obviously at your own risk.

If you are using Stainless replacement bolts with Nylock nuts the actual torque is less critical but more easily set as you can use a standard torque wrench with a spanner holding the other end.

Drop the car, put the tools away and go for a drive.

It is prudent to recheck the mountings for tightness after 50-100 miles.

Review - Update

Can confirm the despite an increase in rear roll stiffness the whole ride of the car is much smoother and more supple - I am happy that the car actually does ride more smoothly, handling the bumps better and the corners much flatter.

I can only put this down to the new bar actually floating in its bushes rather than being clamped solid which the original I took off was, its rubber bushes seem to have welded themselves onto the bar.

 

Edited by octavia5
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All i did was put the car on axle stands, and put the trolley jack under the rear arm one at a time, once the nuts were removed from the drop links. I Just took the weight off of the rear arms and pulled the bolt out. Simples!

Then took the splined bolts out of the frame and removed.

Note to other users willing to do this though, make sure the threads are clean from behind and well oiled with WD-40 or duck oil.

Saves you shearing a bolt or two like i did. Same applies for the drop link splines, get it wrong and the ruddy things snap from the inside out leaving you to fight with mole grips.

How much difference did this make matey.

As you mentioned the VAG bars are a bit cack, i think the same.

I didn't know mine had snapped until i looked under the car, I put a new one on and the car still feels the same as when it was broke.

Edited by Browny_37
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The threads on mine were not that corroded but I agree that if they look bad a wirebrush and some penetrating oil would be a good idea

The official VAG way to change a RARB is documented as doing it while the wieght of the car is on the wheels - something to do with not upsetting the geometry of the rear suspension as well as taking the load off the bar - will amend the guide.

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  • 3 weeks later...

The A5 Chassis covers the Golf MKV, Octavia2, Audi A3 and some Seat models.

I can only put this down to the new bar actually floating in its bushes rather than being clamped solid which the original I took off was, its rubber bushes seem to have welded themselves onto the bar.

on the Golf the bushes are bonded to the bar I asume the skoda's the same, is it because it's lighter/cheeper and so to increase stiffness they bond on the bushes to regain stiffness by limiting "twistable" length? Must be well bonded or have a short life which would make the antiroll action about usless-just a thought- glad there is a noticable improvement
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The bushes weren't bonded to my Anti Roll Bar, once the clamps were removed the bushes opened up to release the bar.

They were slightly stuck to the bar, but i can only imagine thats down to the heat and force put upon them.

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  • 3 months later...
  • 3 weeks later...

so does an A3 whiteline rarb fit the octavia,i hope so as i bought this off ebay and was told it will fit,

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=260602243659

iam ment to be getting this fitted this weekend but iam un-sure it will fit now-any ideas lads

Only just seen this as I dont often look at my old posts but --

Looks the same as mine and as it the Octy has the Golf MK5 chassis it should be the right on, be sure to review my How To in full as you will need to make sure whoever fits the bar uses longer than standard bolts and nylock nuts. If you use the standard VAG bolts wheels side they will only just be holding on as the thread is too short for safety and you don't want a bolt braking halfway round a corner.

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  • 1 month later...

How much difference did this make matey.

As you mentioned the VAG bars are a bit cack, i think the same.

I didn't know mine had snapped until i looked under the car, I put a new one on and the car still feels the same as when it was broke.

can you give me some indication of the size and wall thickness of the broken bar--- hoping you're like me and don't thow anything away :-) cheers Nic

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  • 5 months later...

Hello,

Good post, very detailed.

One question: Are you replacing a broke suspension for a new standard one? Or, are you making a mod, meaning you installed an improved one?

Please, explain. I have a Octavia II 1.9 TDI and the only trade off for me of the car is the too stiff rear suspension.

Do you know any way for softening it?

Thank you,

Oldbeaver

Chile

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on the Golf the bushes are bonded to the bar I asume the skoda's the same, is it because it's lighter/cheeper and so to increase stiffness they bond on the bushes to regain stiffness by limiting "twistable" length? Must be well bonded or have a short life which would make the antiroll action about usless-just a thought- glad there is a noticable improvement

think I was given a bum steer re:bonded bushes-- however that does not mean that they are too tight and therefore restricting the full potential of the bar ie; making it stiffer than it was designed to be, from some initial research the bushes have an "unloaded" diameter approx 4mm smaller than the bar, are most poly bushes sized to "a good fit" please discuss :)

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can you give me some indication of the size and wall thickness of the broken bar--- hoping you're like me and don't thow anything away :-) cheers Nic

2mm-3mm at the most, there wasn't much wall thickness to it at all.

I've no idea how it broke either. Was whilst pulling onto the drive that it caught the floor, and i heard it.

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2mm-3mm at the most, there wasn't much wall thickness to it at all.

I've no idea how it broke either. Was whilst pulling onto the drive that it caught the floor, and i heard it.

thanks for that-- with a bit more digging (for any other anorak's like me out there) they come in:-18.5x2.5--19.6x2.6--20.7x2.8--21.7x3-and-21.7x3.6 :)

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  • 5 months later...

Hi everyone,

I could be corrected here but I'm pretty sure that because a swaybar is essentially a torsion bar, the central part of the tube actually does no work at all, with the outside wall twisting.

Hence Volkswagens use of a hollow bar is actually the best way to go due to it's lighter weight.

Unfortunately, it is harder to source an aftermarket bar made of tube as it costs more to produce.

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Hi everyone,

I could be corrected here but I'm pretty sure that because a swaybar is essentially a torsion bar, the central part of the tube actually does no work at all, with the outside wall twisting.

Hence Volkswagens use of a hollow bar is actually the best way to go due to it's lighter weight.

Unfortunately, it is harder to source an aftermarket bar made of tube as it costs more to produce.

I guess you've seen the Whiteline website/links there's quite a bit of interesting stuff on there, the point i was trying to make was that if the bar cannot rotate in it's mount the effective lenght is shortened and it becomes stiffer in action (bumpier ride?)

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  • 10 months later...
  • 4 months later...

Hi, I bought the same ARB as the original post and thought it best to do a bit a research before jumping in. Seems to be a simple fit but I'd thought I should add a couple of changes Whiteline have done in the 2 years since this guide was made. Firstly they now supply 2 mounts and 4 washers with the new bushes, secondly they supply the kit with two M10x70mm bolts, which I can only assume is for the drop links (as I said, not actually fitted it yet). You still need to supply your own nuts and mount bolts.

Glad to see they have made a few changes.

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