Front Articulation

[TRobbo]

I am wanting to improve the front articulation of my disco without going to extremes - the truck is not a rock crawler. The rear works fine but the front doesnt get the same sort of up travel as the rear (haven't checked droop).

I have seen HSV's cranked arms on here and in 2003 Landyman wrote:

"It all depends on what sort of wheeling you will be doing.. the Rover front can be made to work reasonably well just be drilling the bushes, some decent length shocks and retained springs...

If all you want is a ramp bitch, then fair enough, go the 5 link
Look at how many Rangies have won comps in Oz and Malaysia... AFAIK they all run pretty basic setups."

Have heard of people running 80 series front shocks - is that it or is there anything else I should do?

[defender kev]

I run OME 80series front shocks 10.5" travel with the shock turret spaced about 1inch and sams holey bushes works a treat and couldnt be happier for it cost to set up.

[modman]

i run exactly the same as kev cept ride pro shocks, works a treat.
make sure all bushes are rubber, and the front springs aren't too stiff.
david

[Bush65]

Changing shocks or cranking radius arms will not help with up travel.

Generally you will have more up travel at the rear because there is more travel until the axle hits the bump stops.

If you front is not getting to the bump stops, your springs may be too stiff.

You didn't say what kind of disco - I or II?

The front radius arms try to twist the axle housing during articulation, acting like a large sway bar opposing articulation. The more flex in the bushes the better the articulation

I assume you also have a sway bar fitted to the front. The springs sway bar and radius arms together, is the most likely reason why you do not get as much articulation from the front.

Try disconnecting the links from the front sway bar and tie the sway bar up out of the way. Leave the rear sway bar. Then give it a go.

Drilling through the rubber in the radius arm bushes improves the flex. The holes are parallel with the sleeve and located vertically above and below the sleeve (some stock Landcruiser bushes are like this). You want the bush to flex more as the axle housing twists, but retain the same stiffness for and aft (to resist braking forces).

Cranking the radius arms helps articulation when you have lifted suspension. The lift changes the angle of the arms at the chassis mount, and flexes the rubber bushes when the car is at rest. Cranking the arm relieves the flex in the bush, making it easier to droop further, during articulation. It also reduces wear of the bushes.

With longer travel rear suspension, it is best to retain the top of the springs (the bottom is aready retained). This improves stability and the retained rear springs force the front to articulate more.

[TRobbo]

Thanks John. It's a series one with 2 inch ome spring lift. Not sure of the spring rates but up front there is the usual arb bar and 8274 winch.
The sway bars have already been removed and hence the rear works really well. I suspect it may be spring rate up front and the bushes holding it back (they are rubber). What size holes do you drill in the bushes?

[Bush65]

Thanks John. It's a series one with 2 inch ome spring lift. Not sure of the spring rates but up front there is the usual arb bar and 8274 winch.
The sway bars have already been removed and hence the rear works really well. I suspect it may be spring rate up front and the bushes holding it back (they are rubber). What size holes do you drill in the bushes?

My comments/explanations were concerning the points in your post at the beginning of this thread.

I don't have any experience with ome stuff and have no clue what their specs would be for 2" lift with bar and winch on front.

Radius arm rubber bushes have an outer and inner steel shell. And some have a third steel shell between the inner and outer shells. The 2 shell type is best for flex.

The dia of the hole that you can drill through the rubber depends on the space wetween the steel shells, whether 2 or 3 shell type.

When rubber is drilled, the surface of the hole is not the same as the moulded surface and is a point where the rubber will start to deteriate. Haultec make specially moulded holey bushes and you would probably be better purchasing a set of these instead of drilling your own - contact Ruff on this board and he will sort you out.

[TRobbo]

Thanks John - I sortof expected the bushes would wear out pretty quick if drilled. I'll contact haultech.

[takearidewifme]

before i mod'ed my front to a 5 link I ran 80 series shocks and removes the front radias arm bolt from the passengers side when I got off road. this stops the bind up caused by the 2 bushes fighting eachother during flex. Again this will wear your bushes quicker .....but after 12 months mine showed not a great deal of wear... remember to replace it when driving home though it maked the front feel like a boat at high speed cornering..

Mark

[Spartacus]

Thanks John. It's a series one with 2 inch ome spring lift. Not sure of the spring rates but up front there is the usual arb bar and 8274 winch.
The sway bars have already been removed and hence the rear works really well. I suspect it may be spring rate up front and the bushes holding it back (they are rubber). What size holes do you drill in the bushes?

My comments/explanations were concerning the points in your post at the beginning of this thread.

I don't have any experience with ome stuff and have no clue what their specs would be for 2" lift with bar and winch on front.

Radius arm rubber bushes have an outer and inner steel shell. And some have a third steel shell between the inner and outer shells. The 2 shell type is best for flex.

The dia of the hole that you can drill through the rubber depends on the space wetween the steel shells, whether 2 or 3 shell type.

When rubber is drilled, the surface of the hole is not the same as the moulded surface and is a point where the rubber will start to deteriate. Haultec make specially moulded holey bushes and you would probably be better purchasing a set of these instead of drilling your own - contact Ruff on this board and he will sort you out.

so to revive an old thread...

is it right/ok to drill 4 holes around the bush or is it to many?
im guessing placement is another factor ie: middle or towards the oustide

[GRIMACE]

just get a set of holy bushes from Sam Overton (haultech engineering)...

If you do drill em urself you dril the holes above and below the sleeves for the bushes, as thats the way the diff binds when rotating (up and down).

the wholes would be almost usless if they were infront or behind... and also dont drill al the way through the bush. the whole depth should be about 15-20mm (in a 50mm wide bush)

cheers anthony

[Bush65]

When one front wheel gets pushed up to the bump stop (and the opposite side droops):

the rubber in the lower half of the front bush is compressed

the rubber in the upper half of the rear bush is compressed

The opposite happens on the side where the wheel droops.

The bushes only compress a small amount before they start to limit flex.

Compress is a bad description, as rubber can't be compessed. It's volume doesn't change, but has to deform into a different shape.

The only free space for the stock bushes to deform into (during articulation) is out to the sides. But this is limited by the vulcanised bond between the rubber and the steel shells. It is worse for the bushes which have a third shell (between the inner and outer).

When the bush is forced to deform a large amount, the rubber is highly stressed, as is the vulcanised bond to the shells. This is what causes the bushes to flog out.

The haultech bushes have a hole which the rubber can deform into (105 series landcruisers also have holes, but not as extreme). This reduces the resistance to articulation and the stress in the rubber and bond.

Whatever you do, don't put any holes in the front or back of the bush, as we don't want the axle to flex in the forward or backward direction (especially under hard braking).

[rick130]

according to those that have done it, self drilled bushes tend to flog out fairly quickly. As the fella's above have suggested, get some slotted bushes from Haultech, and make sure you have access to a big press when you go to swap them out. (speaking from experience )

[amshaw]

What kind of $$ are we talking for the bushes....just a Ball Park number will do.

Im just getting into the whole suspention thing...looking for a lift ...but all this is great reading....even if I dont understand much of it

[rick130]

honestly can't remember what I paid. Best email/contact Haultech or PM one of the boys on the board here.