What goes thump in the Disco?

[Utemad]

Hi all,

I get a loud thump sometimes in my Disco1. Generally when I move away from a standstill. Sometimes it thumps straight away, other times a couple of seconds after and more often then not it doesn't do it at all. From what I have read it would appear to be the rear A frame balljoint. However I cannot replicate the thump or any movement at all by rocking the car on the handbrake or levering things. The A frame balljoint (and everything else) appears to have zero movement.

The noise started when the rear suspension was articulating and now does it as described above as well. Sometimes if you go over a speed bump it will thump three or so times in quick succession.

I tried to remove the A frame ball joint today just to get a close look at it (I have a new one to put in) but couldn't even get it to release from the diff housing. Even after bashing it, driving on it with the nut loose and then bashing it some more.

I've tightened all the body mounts, torqued up all the suspension links (front and rear) and checked the rear shocks and rubbers. Nothing has changed.

So if you know of anything in particular that it could be or if you the A frame balljoint could do this without having any visual movement when rocking it then let me know.

Thanks.

P.S. I know the answer is to rebush the rear end but without easy access to a press that won't happen til Jan when I have some time off work.

[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.

[justinc]

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??:p:p


Hope this helps J

JC

[Utemad]

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.



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


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.


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.


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.


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

It's in the garage on the floor ;)

[Utemad]

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.

[justinc]

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.:p
JC

[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?

[justinc]

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:mad:)

JC

[Utemad]

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.



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

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 :wasntme:

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 :cool:

[justinc]

mmm the plot thickens.

Give me a call on 0408 995 635 when you are pulling it apart etc and I'll try and help 'remotely':) You can send pics to this phone number too if you like.


JC

[Utemad]

Thanks JC.

If I do end up pulling the diff out (meaning I don't find it elsewhere) then I'll give you a call.

I guess it could be in the front diff too but the clunk feels rear and it doesn't come through the steering.

I'll drop the rear swaybar now and see what happens on the drive to work tomorrow.

[justinc]

Thanks JC.

If I do end up pulling the diff out (meaning I don't find it elsewhere) then I'll give you a call.

I guess it could be in the front diff too but the clunk feels rear and it doesn't come through the steering.

I'll drop the rear swaybar now and see what happens on the drive to work tomorrow.

:thumbsup:
One more thought, You did mention the body mounts, but have you tightened the ones under the footwells? I know they are forward, but I have chased a clunk in a D1 before that turned out to be loose footwell body mounts, all others were tight.
JC

[Utemad]

I tightened all the ones I saw. Will double check tomorrow.

The only body mounts I had trouble with were the very rear ones. The top of the bolt is obscured by the bumper. They are fairly tight but could be tighter.

What do you use to hold the bolt while you tighten the nut? Surely you don't have to remove the rear bumper.

[justinc]

:D I have a selection of specially bent 9/16" ring spanners for these tasks...:cool:

JC

[Utemad]

I have a few incomplete sets of cheap spanners (from before I saw the light and bought Sidchrome). I might just make up some of those 'LR special tools' :)

[Utemad]

I'll drop the rear swaybar now and see what happens on the drive to work tomorrow.

It's not the swaybar.

This weekend the ball joint is going to cop a real flogging. I'll be the one to decide if it comes out or not :twisted:

[Utemad]

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 was thinking about this as I clunked over the speed bump at work. It would be going clunk as I go over the speed bump as the back end would unload slightly at the crest of the bump.

[RonMcGr]

Hi all,

I get a loud thump sometimes in my Disco1. Generally when I move away from a standstill. .

Had one this morning, frightend the c**p out of me!
Fortunately it was only the engle fridge falling over.. strap came loose :)

[cookiesa]

[quote=Utemad;652411]Not the most common name in Oz but I have noticed we aren't the only two on this site.

Well Hi Justin... and Justin, It's Justin.

Have to say I was going to make the towbar comment. My mate had an issue with a "clunk" from his Patrol for ages we were looking all over it and then one day another mate was visiting while we were checking fluids etc and walked straight in to the tow bar tounge.... clunk.. Thats it! (Sometimes it is the most obvious things.... LOL :()

[Utemad]

Well I have removed the A frame balljoint and the carrier (still together).
I cannot feel any loose movement in the ball joint when I move it through its entire movement range nor is there any up and down movement.

However what is different is I have a new genuine LR balljoint here and I cannot move the balljoint at all. It is seriously tight.
So is the fact that I can move the old balljoint any way I like with minimal resistance whereas the new one is stiff enough to toss the old one?

AFAIK the old one has 191000kms on it as AFAIK it has never been replaced.

I'll swap them anyway as I have nothing to lose.

[Blknight.aus]

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?

if your ever out my way the easy way is to let me have a Mk I and an ears at it and that will give you an answer on that since its a potential safety thing I'll even wave the obligatory BBQ and Beer since its Xmas and all


Well I have removed the A frame balljoint and the carrier (still together).
I cannot feel any loose movement in the ball joint when I move it through its entire movement range nor is there any up and down movement.

However what is different is I have a new genuine LR balljoint here and I cannot move the balljoint at all. It is seriously tight.
So is the fact that I can move the old balljoint any way I like with minimal resistance whereas the new one is stiff enough to toss the old one?

AFAIK the old one has 191000kms on it as AFAIK it has never been replaced.

I'll swap them anyway as I have nothing to lose.


if you can move it easily by hand (or if you invert it and can make the pin "waggle" just by shaking it then its out of spec, It'll last forever but it'll clunk on occasions.

at those sorts of KMs id be expecting it to have let go by now especialy if the vehicle gets forded or sees beach work.

[Utemad]

Thanks Dave.

I can't make it waggle by shaking it but it is easy to move. I can waggle it by holding the shaft with the carrier still attached though being heavy. It was fun trying though :)

I've had the vehicle on the beach twice and and it gets driven though creeks on occasion but it would not have been submerged. Not by me anyway. I've had it for the last 37000kms.

[justinc]

So Justin its Justin again, and no doubt Justin will be here soon too and we can all ask Justin how you are going with fitting the new A frame ball joint???

Justin number 3

[Utemad]

Hi Justin,

The old ball joint is still in the carrier. My brother came over and has taken it to his house where he has more appropriate tools.
My soak it in lanolin for a while and then hit it with a big hammer didn't budge it a mm :angel:

[justinc]

Hi Justin,

The old ball joint is still in the carrier. My brother came over and has taken it to his house where he has more appropriate tools.
My soak it in lanolin for a while and then hit it with a big hammer didn't budge it a mm :angel:

I find it easier to cut the lugs off the side where it bolts on to the carrier, and then simply put it in the press...:twisted:

JC

[Blknight.aus]

if you have no joy at your brothers and you can get it my way I'll take it to work and put it into the press for ya

[Utemad]

Thanks guys.

We have cut the wings off it and I'll find out tomorrow if he had any luck with it. If he doesn't I'll just take it to an engineering place near my work on Monday. I just don't like doing that though. If I can't do it myself then I just feel like less of a man.

[chazza]

Thanks guys.

We have cut the wings off it and I'll find out tomorrow if he had any luck with it. If he doesn't I'll just take it to an engineering place near my work on Monday. I just don't like doing that though. If I can't do it myself then I just feel like less of a man.

Know the feeling Ute:( Have you thought about making yourself a press? It is not particularly hard to do and a ten-ton truck jack will do most jobs:D

Cheers Charlie

[Utemad]

I do plan on building my own press and between myself and my Dad we have the parts but I don't have the space to put it (townhouse) and he lives too far away (although has 10 acres and two huge sheds).

When I get a regional position I'll be kitting out my own big shed :)

[Utemad]

Still no luck.

Looks like I'll be driving my wife's Corolla to work tomorrow and taking the balljoint to get pressed out and the new one pressed in.

Unless someone on the southside of Brisbane has a press they want to try out :)

[Utemad]

Well after all the hassle of trying to remove and refit the balljoint into the carrier myself, I dropped it off to the mechanic we use for work and he did it for a 30 pack of Coke (a man after my own heart).

When it stops raining I'll bolt it in and see if it fixes the clunk.

[Utemad]

The new balljoint is fitted (yesterday). I took the car for a quick spin around my area and the thump appears to be gone. I won't be able to drive it again until probably Sunday but I reckon it is fixed.

Thanks all. Hopefully this thread is done but I don't think my Disco will ever be 100% free of noises :)