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clunking noise from the rear of the car

stocky

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just noticed something different with my car lately.
if i am travelling, say, above 50 and i let it idle at that speed for a while for a while, when i press the accelerator i get a bit of a clunking noise from the rear. its makes one noise and then its fine. sounds like its from the diff.
is this normal, or could something be wrong?
 

Morton

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My old diff did that, when it had a busted centre bearing, cracked panhard bar rubbers, cracked upper and lower control arm bushes and rooted diff bushes. After I replaced them all and fitted a vs diff and lower arms, the clunking was fixed. I suspect it was the centre bearing that caused the clunk, but it could be a sign the diff is on the way out. If you get lucky, you can score a new one fairly cheaply. I got my vs diff fitted for $150 with the lower control arms.
 

pandaman

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Sounds like backlash, it happens when your driveline starts getting old and you start getting play between components. Or it could just be rooted bushes, easiest thing to check would be to look at the rear suspension bushes make sure they're intact, if so then theres probably some backlash in the diff.
 

savage1987

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Cheers guys. I was having the same trouble, just wasn't too sure how to explain it lol. What diff options do I have? I'm looking for LSD . . . any bolt-overs from other models? Is there much modification of rear suspension required?

And I don't really want to change the ratios too much, if I can help it . . . heaps of highway driving . . .

Cheers
Sammy B
 

bradcad

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i'm having similar noises, however i also seem to have a bit of 'wobble' in the ass end when coming to a full stop. Anything harder than a gentle stop and you can feel the back bouncing before coming to a stop.

yes shocks are new...
 

pandaman

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savage1987 said:
Cheers guys. I was having the same trouble, just wasn't too sure how to explain it lol. What diff options do I have? I'm looking for LSD . . . any bolt-overs from other models? Is there much modification of rear suspension required?

And I don't really want to change the ratios too much, if I can help it . . . heaps of highway driving . . .

Cheers
Sammy B
An LSD diff from any VN sedan or live axle VP sedan will definitely fit. Other than that, Diff centres from VN/VP wagons and utes will also fit, but not too sure about the whole unit, theres probably a thread on it around here somewhere. Just do a search for LSD in the VN section, should turn something up.
 

Stevob

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bradcad said:
i'm having similar noises, however i also seem to have a bit of 'wobble' in the ass end when coming to a full stop. Anything harder than a gentle stop and you can feel the back bouncing before coming to a stop.

yes shocks are new...
You've got some worn bushes in your rear suspension. Possibly panhard rod bushes.
 

immortality

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clunk when accelerating after coasting could be a badly worn universal in drive shaft, easily diagnosed by jacking up the car and manipulating the driveshaft by hand. any visible movement means it's shagged. otherwise bushes or to much play in the old diff. if your gonna get an LSD fitted, they should be able to sort that when they fit the LSD center and re-shim to set the crown to pinion back lash.
 

Benji

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yeah uni joint or centre bearing is what id be putting my money on
My car does the same thing and its the centre bearing

Cheers Benji
 
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