Voided or Non-Voided bushes live rear axle

[orlando]

I have read that its important to maintain voided rather than non voided bushes in the trailing arms of live rear axle commodores. Can anyone elaborate on which bushes they are upper or lower and whether or not this is an accurate statement? Have done most of the bushes, shocks and springs in my car other than the trailing arms which is why I ask.

thx in adv.

[pjdm1980]

Not to my knowledge, you just put them in and go unless they have grease nipples.

[Cheap6]

The voided bushes are on the upper control arms. The voided bushes were included on a model update, with VP I think, so in theory they should be superior. The change may have been to improve noise or bump supression though, so "superior" may depend on your priorities.

Having driven a few cars back to back with the bushes changed from one type to the other, I can say that I can't pick any difference between them at any speed I'm willing to drive at on public roads, but others might.

If you are using the voided type they are meant to be pressed into the control arm with a particular orientation - marking and matching the way in which the old ones were fitted is reasonably likely to result in the correct orientation.

[immortality]

thats odd. i did the upper trailing arms on the VS using urethane type bushes and they were the solid type as listed in the suppliers catalogue (can't remember if it was nolathane or noltec).

in my opinion, voided bushes are more forgiving. basically they allow more movement. if your after comfort then go for it. if you want a firm ride with better control then fit the urethane solid type.

[orlando]

"The four-cylinder Rekord suspension, while state-of-the-art when it first appeared in Australia in 1978, depends heavily on its voided bushes and its Panhard rod to hold it together over choppy surfaces. These bushes have cutouts that allow key locating arms to twist easily in some directions but not others. Without them, no Commodore live rear axle suspension can work. Yet they were not developed to take the huge torque of a V8 and they can tear. The Panhard rod which can create a jacking effect in certain cornering situations is also vulnerable to wear in its bushes.

There is a tendency in some quarters to drop the ride height and replace the voided bushes with solids. This might work in containing big V8 grunt for the strip but it can introduce bump steer that can be fatal on uneven road surfaces."

Found the article. I assume tthis applies to the sixes as well.

[Cheap6]

There seems to be a bit more to this. Rather than rely on my memory again I looked in the relevant VP manual and found:

(Paraphrased) "On sedan vehicles fitted with either FE2 or V5W, the upper right hand bushes are of the voided type.

The upper LH bushes on FE2 and V5W, and the bushes for both upper control arms on all other (VP-?)models are solid.

On sedan and wagon with standard suspension or wagons with either FE2 or V5W, the lower arm bushes (F+R) are of the voided type (+ see note below re. S=Packs, w' FE2)."

The orientation of the front bushes in the lower control arm changed (rotated 90 degrees) with VP over VN (and earlier?).

On sedans with FE2 or V5W except S-Packs built from 24/08/92, L586996, the lower control arm bushes are of the solid type. The voided type was introduced to "reduce harshness in line with S-Pack customer expectations".

[centy]

holden mechanic i worked with a few years ago said voided were better. he never explained why.

[immortality]

There seems to be a bit more to this. Rather than rely on my memory again I looked in the relevant VP manual and found:

(Paraphrased) "On sedan vehicles fitted with either FE2 or V5W, the upper right hand bushes are of the voided type.

The upper LH bushes on FE2 and V5W, and the bushes for both upper control arms on all other (VP-?)models are solid.

On sedan and wagon with standard suspension or wagons with either FE2 or V5W, the lower arm bushes (F+R) are of the voided type (+ see note below re. S=Packs, w' FE2)."

The orientation of the front bushes in the lower control arm changed (rotated 90 degrees) with VP over VN (and earlier?).

On sedans with FE2 or V5W except S-Packs built from 24/08/92, L586996, the lower control arm bushes are of the solid type. The voided type was introduced to "reduce harshness in line with S-Pack customer expectations".

thats a interesting article. it shows that holden have used voided bushes in certain locations only most likely to do with the way the suspension is loaded up.

i have a nolathane car upgrade kit downstairs and all the the bushes are of the solid type. it includes all the bushes for the car.

reading the last line of your post re-inforces the point that voided bushes are used to reduce harshness in the suspension aka a more comfortable ride.

There is a tendency in some quarters to drop the ride height and replace the voided bushes with solids. This might work in containing big V8 grunt for the strip but it can introduce bump steer that can be fatal on uneven road surfaces

i think this is a very dangerous statement to make. there are many reasons that can lead to bump steer but suspension bushes generally aren't one. i have had various commodores over hte years that have had various bushes upgraded with urethane type solid bushes and there has always been a improvment over the stock rubber bushes. it may make the ride a little harsher but that is a givin when you want performance over comfort.

these days there are a great vaviety of urethane type bushes on the market. so you have a choice of hardness. this is equates to voided and non voided bushes. the benefit of urethane is that it returns to it's original shape after deflection or loading and is much more resistant to wear and memory retension that rubber bushes tend to suffer from. therefore urethane bushes tend to hold the suspension geometry better which means better handling and increased tyre life because the wheel alignment hold better