BLIMEY! ARB carnage

[dave friday]

A few years ago the bay window vans were breaking their arb,s so i recon it's metal fatigue!!.

[jed the spread]

I've heard its contagious.... you're next Jed....

I have had my fair share of epic fails as you know

Jed

[v-lux]

Had a closer look at it today and i reckon Jason and Dai are right.

There's definitely signs of a crack that's been there a while. Certainly explains how i could shear so dramatically.

Think i'm sorted for a replacement, thanks Max and Caddy! Although, does anyone know if an E reg has got the same ARB as a J plate? Seem to remember there being a 19" and 21"...

[hugomonkey]

i can measure both in the morning when i get home from work

[max and caddy]

So you want it then? Both are 21mm... Just a different shape as far I can see... But the ends are in the same place so why is a mystery.. Unless someone has the answer? I'm away down south until Friday so hope your not too desperate..!

[syncropaddy]

This thread confirms two things .....

Poly bushes take out too much compliance and puts too much stress on the components they are fitted to and components down the line. This causes failures.

Syncros don't need ARBs particularly when they are lifted!! Proof of the pudding is that you didn't realise that it was broken even after driving with it that way.

[max and caddy]

My views on arbs is they help with motion sickness... That's important to me as go green very easy!

[axeman]

This thread confirms two things .....

Poly bushes take out too much compliance and puts too much stress on the components they are fitted to and components down the line. This causes failures.

Syncros don't need ARBs particularly when they are lifted!! Proof of the pudding is that you didn't realise that it was broken even after driving with it that way.

i dont know about the poly bushes as i have only the ploy steering rack bushes and was very impressed with them, i have to wonder though if i replaced the bushed with the new vw rubber would the effect have been the same?

with regards to the arb, just before coney i replaced the vc and in the process both the drop link threaded sections sheared, so i was forced to not fit the arb, and i have to say that i did not really notice difference in the way the van handled. having said that once i get the drop links repaired it will all go back on.

neil

[lloydy]

I drove around with mine off for a few days, can't say i noticed much difference.. Maybe it would come in to play if to avoid an accident you had to swerve left/right quickly?
I toyed with leaving mine off, but decided it's a safety component and should be on

[v-lux]

it's a safety component and should be on

This is it, why would there be one otherwise? Unless it's just a requirement thing for production, but that seems unlikely.

Max and Caddy, no worries, not in a rush. I'll grab it from you at some point.

[Simon Baxter]

All Syncro have 21mm ARB.
Syncro ARB is the same shape at the ends as a 2WD but they different in the middle, I seem to remember.
Purple poly on a standard Van are fine, problems seem to arise when they are lifted, the ones at the bottom of the drop link are too stiff and don't let the links move about hence why we've asked powerflex to make some in their softer yellow compound.
I can't remember the shore rating of the yellow bit it's not far off that of the original rubber.
If you can imagine taking a spring off the front suspension then moving the front suspension throughout its full stroke then you may be able to see what the ARB links go through.
When I do that panel van of mine I'm contemplating chopping the end of the bar off and drilling and tapping the end and fitting some washers to keep the links In place and also thinking about using a ball joint at the bottom of the link to give easier movement in all planes.
I'm also trying to think of an arrangement to be fitted to the Centre of the bar where you can remotely detach the left and the right sides of the bar from each other. That way you can have on road and off road settings, with ARB for the road and detached for.
Pipe dream.
Nissan patrol Y61 had a rear ARB, the left hand rear ARB link had a cable running to it, when the off road button was pressed a solenoid pulled the cable and turned the ARB link into what looked like a damper and basically detaching the rear ARB until you either turned it off or went above 12 mph.

[max and caddy]

Just looked it up because I'm sad like that...251411025 is the 21mm anti roll bar for all t25s, 2wd or 4wd from 1985 to 1992...same part!

But they do have two shapes...this I know for certain as I have both in my possession..off syncros and original fitment...same but different it seems! Non syncro specific anyway, but seems the later bars are less "kinky"

I gotta say it is a very poor design..ball joints would be good exept untill they start to go loose of course...but imagine one wheel up in the arch and one right down...the bar and bushes do well to stay put at all I think but still surprised at where Als broke myself.

Anti roll bar decouplers now is it....that's going to be an interesting one for mass debating over

[hugomonkey]

I drove around with mine off for a few days, can't say i noticed much difference.. Maybe it would come in to play if to avoid an accident you had to swerve left/right quickly?
I toyed with leaving mine off, but decided it's a safety component and should be on

here you go, try and stay awake through this
http://www.youtube.com/watch?v=_liGnV3PTiQ" onclick="window.open(this.href);return false;

[jebiga41]

This thread confirms two things .....

Poly bushes take out too much compliance and puts too much stress on the components they are fitted to and components down the line. This causes failures.

Syncros don't need ARBs particularly when they are lifted!! Proof of the pudding is that you didn't realise that it was broken even after driving with it that way.

I would disagree with both points infact this thread seems to disprove the first if anything whilst polybushes of a certain stiffness will pass on vibrations more than rubber I really can't see how this would have an effect on shearing a 21mm spring steel bar I also strongly with the 2nd statement and am surprised as I really notice the difference when driving the pick up without an ARB especially when going into tight bends and roundabouts I can really feel the body roll and that is a light van, on a heavy camper I would not like to be without the ARB and IMHO I would consider this to be a v dangerous persuit

[v-lux]

Purple poly on a standard Van are fine, problems seem to arise when they are lifted, the ones at the bottom of the drop link are too stiff and don't let the links move about hence why we've asked powerflex to make some in their softer yellow compound.
I can't remember the shore rating of the yellow bit it's not far off that of the original rubber.

I wonder how much the polybushes have to do with it really, i checked yesterday and i've got purple ones on the bar where it mounts to the body, yellow ones on the drop links and standard vw rubber where the drop links fit to the control arms.

The only issue i have had is with the drop link working its way off the end of the ARB, this did happen to be after i had fitted the yellow upper drop link bushes, but there's nothing to say that this wouldn't have happened with the standard vw ones, all conjecture really.

I still have the standard vw lower bushes, so they don't come into this.

As for the upper purple ones, in my opinion i don't think they really can have that much effect on the outcome here, they do their job providing a mounting just as they are designed to. Perhaps they are a bit harder compound than the vw ones, but it seems unlikely to me that they would be able to cause excessive stress to the point of causing a 21mm piece of metal to suffer.

Metal fatigue in a highly stressed component coupled with the previous huge release of energy from when the drop link popped off seems a far more likely cause for this breakage to me.
As Simon has mentioned, the forces going through that bit of metal must be huge!

I personally agree with Paul about the ARB, i think i can perceive a difference in how the van handles without it on there, which is why i have always opted to keep it. Just looking at how it works/what it does is enough in my mind to conclude that it must make a difference.