Rear Axle Clunking Noise - Help needed

[jazza21]

I have done multiple forum searches before posting this and not found anything, so I apologise in advance if this has been answered before...
I own a 97 VS Sedan and it has developed a clunk in the rear end, which over the past month has become louder and more prominent. This clunk can occur when;

* Engaging drive, after having been in reverse and vice-versa
* Slowly passing over speed bumps with brakes gently applied. This happens after both wheels have passed the crest and start the decent on the other side
* Going over general bumps in the road at any speed

Now I have raised the rear of the car and got it on stands, handbrake and Park engaged, front wheels chocked. When loosening the wheel bolts on each side I have found I can actually cause the axle to rotate maybe 1 degree or so, back and forth, and in doing so make this clunk occur.

I suspect it's something important so I want to find out all I can, as soon as I can. I do not know if I have LSD, it's not something I know how to check for...
Thanks
Jazza

[hako]

I presume you have the solid rear end like mine so thats probably the control arm - one for each side and they stop the axle from rotating. Cost about $26 each and simple to fit.
Here's a link:
Commodore VR-VS

[=Calais v8=]

just a note for checking if you have an LSD: check to see if it has an LSD by reading the tag on the diff (it will say "high performance LSD" or something along those lines), or while it's on stands, turn one rear wheel, and if the other turns the same direction, it has an LSD. opposite direction, single spinner.

[jazza21]

I presume you have the solid rear end like mine so thats probably the control arm - one for each side and they stop the axle from rotating. Cost about $26 each and simple to fit.
Here's a link:
Commodore VR-VS

By solid rear I take that to mean not LSD?
Based on what =Calais v8= says with the direction opposing wheels rotate, my car does not have LSD. I have noted however that when checking for this "clunking" and manually rotating one back wheel (in park, handbrake on), the other wheel does rotate in the other direction equivalent to how much I turn the one I'm holding. So it's as if it's internal, within the axle mechanism. I paid particular attention to the suspension, sway bar and even the drive shaft when doing this, and there was no perceivable movement up down left or right, just rotation of the axle.

[Nanos]

I too have the same noise at the moment. I know its not suspension as i changed all the bushes about 4 months ago. Noise started about 1 month ago.

I am thinking its the something in the handbrake. That is where i noticed the sound coming from(inside the rotor).

Going to pull apart the handbrake gear next week and have a look.

[jazza21]

Hmm, I do not think it is the handbrake, as if it was it would only make the noise when it's "on".

[hako]

By "solid rear" I mean non-independant suspension or conventional suspension. If you get this "clunk" with the handbrake on (as you indicate in message 1) when loosening the wheel bolts and the "axle" moves 1 deg or so each direction and get the clunk then that would seem to mean that the whole differential assembly is rotating which gets back to worn control arms.

[Nanos]

The reason i thought my problem which is simialr to the one being question in this thread is if the handbrake is not on and the handbrake shoes are badly worn and same with the return springs then you would have loose componets while driving.

I would not think a handbrake would make loose noises if it was applied as all the componets are under pressure.

I once had a car many years ago with a drum rear end set up. When a compnet failed it too gave this exact noise. Since a VS handbrake works the same as a drum brake set up and every bush in the rear and the shocks and springs in my car have been changed in past few months this leads me too looking at the brake set up.

[DannyboyDS]

i'd look at the transmission mount and your uni joints on the tail shaft, that'd be my guess, a quick inspection around the suspenion components in the rear will tell you if they are to blame, they will either appear totaly roooted or you will see dents and scratches where contact is being made.

[=Calais v8=]

is your car lowered with IRS? could be a cracked Cradle.

[jazza21]

is your car lowered with IRS? could be a cracked Cradle.

No I do not have IRS... I am going to look into Hako's recommendation and see if it's the Control Arms. The only thing is I haven't been able to get back under it again and I have no idea where I should be looking for them.
*Sigh*

[Clutchy]

Its backlash in the diff at a guess thats why it does it when you turn it with ya hand it will get worse till it lets go.

[jazza21]

Its backlash in the diff at a guess thats why it does it when you turn it with ya hand it will get worse till it lets go.

I reckon that's what it'll be if it's not the upper suspension struts. Car will be up on the stands as soon as this rain stops long enough.
Thanks

[azkwazere]

This may sound odd but check your tail shaft to diff flange bolts...

Mine were loose(read dodgy mechanic) and it was *cluncking* when ever i slowed enough for the tail sahft to stop momentum.

aZk.

[hako]

Here's a pix of the diff assembly:

[controlled chaos]

have u been doing burnouts by any chance, u might have a ****ed diff maybe, take the back plate off and check, maybe, it happens

[jazza21]

have u been doing burnouts by any chance, u might have a ****ed diff maybe, take the back plate off and check, maybe, it happens

Haha erm... No.
I am not the kind of guy to be doing burnouts!
Besides, I don't have cheap tyres, so burning them away would be stupid of me! Bloody car costs me enough as it is.

Here's a pix of the diff assembly:

Hako, as you originally suggested, I have looked at the rear suspension upper control arms on each side... And the bushes/rubber at the axle ends are screwed! So now the challenge is to replace the rubber...
Jazza

[jazza21]

Here are two pics from the culprit.

[hako]

They would definitely cause a clunk! Now you've got to hope the wear in them didn't put extra strain on other components and bugger them too.
At least they are easy to change.

[jazza21]

They would definitely cause a clunk! Now you've got to hope the wear in them didn't put extra strain on other components and bugger them too.
At least they are easy to change.

Wear the new ones in?
I couldn't wait for those refurbished ones to be delivered so I went to Repco and had a look at what they had. Choice was either a Nolathane bush kit ($85) or a complete pair of Nolathane control arms ($135). Decided against the kit as it required me to somehow pull out the old parts then push in the new - which to me seemed impossible without having the right tools. It could have cost me even more money this way than with a complete set, especially if I'd fudged the old arms up in the process...
So now I've fitted the new Nolathane (square tubed) arms and, you guessed it, noise eliminated. They're supposedly stronger than the original, though to be honest the only thing that went before was the blue neoprene or whatever it was so I doubt there'll be much difference.
One last thing - It appears there is actually a minor amount of 'play' in the rotation of the axle from one direction to the other, which of course lead me down the wrong path. This I can put down to a small-ish gap between the gears inside the Diff, hopefully due to wear and tear. Just one more thing to add to the repairs list.
The car will be 11 years old in April so who knows what's going to go next... Bloody Commodore (but I still luv you )
Thanks for all your help, very much appreciated
Jazza

[jas98]

i replaced the bushes with the purple polyutherane ones that i got for 30 bucks (for 4 bushes) from supercheap and when i was in there today they were 30 bucks normal price so if anyone needs these rubbers go to supercheap....there cheap there for some reason as repco wanted like HEAPS more and me local parts place wanted 17 bucks EACH for normal rubber ones!!

but yeh then again i have a 6 tonn press which came in handy when replaceing the rubbers etc....

[hako]

Holmart have brand new control arms with rubber bushes fitted for $26.40 each which seems pretty cheap. But for polyurethane that price from Supercheap is good.