Thread: What goes thump in the Disco?

before you go any further, just to eliminate them jack each wheel and give them a rock to make sure that its not bearing or swivel pin free play. Id suspect the ball joint.

Howdy Justin it's Justin,


Have you;

Tried levering the A frame ball joint up and down with a breaker bar? Even a small amount of vertical play will be enough to cause a 'clunk'.

Tightened the upper A frame bushes to Chassis bolts, TIGHTLY? 1"1/8 socket and a loonngg bar?

Checked the pinion Flange nut? If you have a rubber coupling tailshaft pinion flange, then they are prone to making a clunk when loading up, and this is due to the splines shifting and going 'clunk'. Try getting someone to load up the drive train or rock it A LOT with park brake on while holding the pinion flange.

If you have a stabilizer bar, the rear links can sieze and cause a noise. Especially during articulation. Try dropping the sway bar off.

And last, but not least, HAVE YOU REMOVED THE TOWBAR TONGUE??


Hope this helps J

JC

Originally Posted by justinc

Howdy Justin it's Justin,

Not the most common name in Oz but I have noticed we aren't the only two on this site.

Originally Posted by justinc

Have you;

Tried levering the A frame ball joint up and down with a breaker bar? Even a small amount of vertical play will be enough to cause a 'clunk'.

I've levered it all over and it doesn't appear to move

Originally Posted by justinc

Tightened the upper A frame bushes to Chassis bolts, TIGHTLY? 1"1/8 socket and a loonngg bar?

I torqued all the suspension links to spec. I remember these were hard to get at but I am sure I did them. I'll give them another go tomorrow just in case.

Originally Posted by justinc

Checked the pinion Flange nut? If you have a rubber coupling tailshaft pinion flange, then they are prone to making a clunk when loading up, and this is due to the splines shifting and going 'clunk'. Try getting someone to load up the drive train or rock it A LOT with park brake on while holding the pinion flange.

Funny you should mention this. I did drop the tailshaft and check the torque of the pinion nut. I have replaced the rubber donut with a four bolt flange about 2 months ago.
There was some movement in the flange but it was not loose to the pinion. I could however induce some clunk in the diff by rocking the pinion a little bit. It gave a louder clunk than usual sometimes. This is consistent with the clunk I can feel in the vehicle. I don't know if this was like this before or not.
Problem is I can't see this giving a thud through the cabin and how would it give this clunk a few seconds after I have taken off from a standstill? The clunk sometimes happens when I am in first gear and smoothly accelerating away. I would have thought the load on the diff would be consistent so it would have clunked either as soon as I loaded it up or just after I unloaded it.
I checked the oil level and it was fine.
Another interesting thing is at the end of my street I turn right. At this point it will clunk 9 times out of 10 as soon as the vehicle moves. Interesting point I think but it may be just that is at the start of the journey. It doesn't always clunk on corners. Just that corner.
So this is a possibility but I just don't see it.

Originally Posted by justinc

If you have a stabilizer bar, the rear links can sieze and cause a noise. Especially during articulation. Try dropping the sway bar off.

I had the rear swaybar off for a while and put it back on about 4 months ago with new rubbers on the bar to the links bolts. I'll unbolt it and tie it up and see what happens.

Originally Posted by justinc

And last, but not least, HAVE YOU REMOVED THE TOWBAR TONGUE??

It's in the garage on the floor

Originally Posted by Blknight.aus

before you go any further, just to eliminate them jack each wheel and give them a rock to make sure that its not bearing or swivel pin free play. Id suspect the ball joint.

I just went outside and shook each wheel and rocked the car sideways etc and none of the wheels feel abnormal. This was without jacking it up though.
I'll do it on the jack before I go too much further.

J, Its J.

I would now be suspecting the side gears and /or the cross shafts in the carrier. This can produce a noise when turning, and articulating as the drive load can shift from side to side within the differential via these components, and this is a common wear point in the rover differential.
I got similar noises when turning and sometimes straight ahead in the ZF fairlane before the side gears broke
Check it by removing the differential and visual inspection. Do it soon as IF it is this, and it does actually break, it can damage the crownwheel etc causing more $$$$
At least the rear diff is easy to get out.
JC

Better check the diff then.

It has an air locker fitted to it.

I know stuff all about diffs. If this is the issue how is it repaired? Where do you get the bits?

Got any photos of good vs bad diff bits?

Originally Posted by Utemad

Better check the diff then.

It has an air locker fitted to it.

I know stuff all about diffs. If this is the issue how is it repaired? Where do you get the bits?

Got any photos of good vs bad diff bits?

J,
If it is an airlocker, then they have about a 50 times stronger centre, and hardly ever fail. Still worth a look though, as the symptoms fit...
Coulkd be loose carrier bearing caps, but they can cause whining too usually. (rather like small children on school holidays)

JC

Originally Posted by justinc

J,
If it is an airlocker, then they have about a 50 times stronger centre, and hardly ever fail. Still worth a look though, as the symptoms fit...

It is an airlocker. Fitted about 12 months ago 25000kms ish. 225/75 16 BFG KO tyres so shouldn't be too stressed.

Originally Posted by justinc

Coulkd be loose carrier bearing caps, but they can cause whining too usually. (rather like small children on school holidays)

JC

There is no whining. We have no kids but my wife has been known to emit a loud whine when it gets hot and dusty

I know ARB changed the bearings when they fitted the locker. I don't actually know what bearing caps are though. Sounds like google is going to get a pounding at work tomorrow