VK - Rear Suspension Advice?

[philbio]

I have just finished the upgrade on the front suspension of the VK (with 27mm front sway bar) and it is now showing that the back needs some attention as well.

I am thinking of replacing the bushes with poly and swapping out the stock sway bar with another. Since the diff is an open wheeler I thought I should go with an adjustable bar in case I put a LSD in later on.

I spoke to a couple of blokes regarding the size of the sway bar and the consensus seems to be get a 20mm and don't get an adjustable bar because they are 22mm (and do not adjust softer only firmer) and will be too hard. Does anyone have any experience on the choice offered?

[vkberlina]

I run whiteline blade adjustable bars front & rear on my VK I do have an LSD. I would honestly buy the same again. Really to make yourt suspension work you need to consider many factors, power train, tyres camber, caster, car weight, ride height, type of shocks, road surface and style of driving etc will impact on your cars handling. The stiffer you make a car the less grip you will have there is a compimise that needs to be reached. So your sway bars can be used on the car in the future if you modify it further I suggest adjustable.
After buying all adjustable gear on my VK i am glad I did, it took many hours getting the right camber & caster ont he front, right sway bar stiffness then on the rear I had to go through the same sway bar adjustments, after adjusting the rear I then had to tweak adjustment on the front. In the end I have a car that handles well in the dry & wet while still maintaining a comfortable ride.

When you fit it make sure you reenforce the mounting brackets ont he body they will tear off otherwise.
You can make it softer with a bit of thought you just need some flat 5mm steel and bolt it too the bar extending the length of the bar this will in turn give the body more leverage and make it softer.

cheers
Scott

[Cane_It]

most definitely leave the bushes pressed into the diff assembly as rubber, and nolathane everything else up back, go an adjustable panhard rod in the back, esp if your considering a diff swap and / or lowering.

for a daily street car i think modding the rear swaybar is overkill, i run a stocky on the back and wouldnt bother changing it.

[philbio]

most definitely leave the bushes pressed into the diff assembly as rubber, and nolathane everything else up back, go an adjustable panhard rod in the back, esp if your considering a diff swap and / or lowering.

for a daily street car i think modding the rear swaybar is overkill, i run a stocky on the back and wouldnt bother changing it.

Thanks for the info, so do you recommend leaving the lower trailing arms rubber or change to poly? and leave the upper arms rubber?

[vkberlina]

Thanks for the info, so do you recommend leaving the lower trailing arms rubber or change to poly? and leave the upper arms rubber?

I’m sorry I don’t quite understand this after changing all the other 20odd year old bushed why would you leave a pair of bushes original? Especially rear control arm bushes in the diff they are easy to change. When you accelerate esp hard these come under enormous loads.
I have actually recently bent a rear control arm due to it flexing under acceleration I am in the process of reinforcing a pair of control arms

Have a look at whitelines range of bushes they are a different compound to nolathane bushes and have a little more give in them, last longer & don’t rattle & squeek as much.

As for a sway bar how can you change one thing without it not affecting another, early commodores like a soft rear end to help steering out of corners but the stock rear sway bar is so inadequate.

Over the age of the car the front caster rods begin to straighten and will affect turning into corners & cause uneven tire wear. Where the rod goes through the bush in the cross member bush usually floggs out & rusts.

You have a 20+ year old car its really suspension maintenance




cheers
Scott

[Tom_1569]

I’m sorry I don’t quite understand this after changing all the other 20odd year old bushed why would you leave a pair of bushes original?

I think hes referring to using new rubber (original) or use nolathene.

I am in the process of reinforcing a pair of control arms

Have you seen these?

[philbio]

I think hes referring to using new rubber (original) or use nolathene.

Yes, I mean to replace the rear bushes with new rubber or poly. So which is it (which bushes rubber/poly)?

[Cane_It]

like i said, nolathane EVERYTHING except the two bushes in the diff, if the rubber ones in the diff assembly are no longer serviceable, replace them with rubber,

go here and read:

Brock Commodores Forums

[Cane_It]

and here:

Brock Commodores Forums

[philbio]

Thanks Chaps

On reviewing the info and threads looks like a good approach is non-voided rubber bushes in the rear of the lower trail arms and poly the rest.

Is there a source for the solid rubber bushes? GM original (looks like pedders may stock some)?

[vkberlina]

I think hes referring to using new rubber (original) or use nolathene.



Have you seen these?

I certainly have seen them they have been around for years, toying around with a couple of designs at the moment, I have concerns about them holding crap and not being able to clean them out easily, they dont really need an entire plate.

As for suspension bushes do some research on the whiteline product it is softer than nolathane and works very well they have loads of good info on their website.

cheers
Scott