Disco 3 suspension creaking

[reb78]

2007 TDV6 Disco 3 on air springs

We have a strange creaking noise from the rear left corner - particularly bad when the suspension is articulating over rough ground.

I got it up in the air today expecting it to be one of the suspension arms or ARB bushes. Top arm on the rear left was replaced three years ago. The rear bush on the bottom one doesnt look great, but the creaking noise seemed to be coming more from the strut. I used my stethascope and when placed on the top of the strut the noise was loudest as i moved the bottom arm up and down. I still wasnt totally convinced.

Spraying WD40 on the strut bushes made no difference.

I disconnected the strut from the bottom arm to try and figure out what was going on. Moving the suspension arms and hub at that point and everything was silent. Weirdly, I couldnt push the strut up and down despite having depressurised the air springs with hawkeye.

Put it all back together and the noise was back and strut would move again with a bar under it.

The top bush on the strut doesnt look great and as i manipulate the bottom arm/hub up and down, I can see the top of the strut moving up and down a little - I am sure this should be tight?

Does this sound like I should bite the bullet and replace the strut and air spring (cant see a lot of difference in price to just do the shock)? Is it wise to do both sides? They are both the same age.

I am half wondering if I just bite the bullet, do upper and lower arms both sides and both air springs/shocks. On the rear, only the left upper arm has been replaced in my ownership (2018 onwards) so the rest could be original at 140k miles.

 

[Ubique]

Sounds like the oil has escaped from the damper and the noise is metal binding.... not unusual for that age.
The test is to remove the damper & airbag assembly, invert, wait a couple of minutes then push downwards on the damper. You'll probably get some oil blowing out of the air pipe connector indicating the damper has failed.
It's good practice to change dampers 'per axle' - TBH, I'd be surprised if the rear arms haven't been done previously for that age & mileage, if it were mine, I'd just replace the damper & airbag assemblies if everything else is OK.

 

[reb78]

Sounds like the oil has escaped from the damper and the noise is metal binding.... not unusual for that age.
The test is to remove the damper & airbag assembly, invert, wait a couple of minutes then push downwards on the damper. You'll probably get some oil blowing out of the air pipe connector indicating the damper has failed.
It's good practice to change dampers 'per axle' - TBH, I'd be surprised if the rear arms haven't been done previously for that age & mileage, if it were mine, I'd just replace the damper & airbag assemblies if everything else is OK.

Brilliant. I was hoping you would read this and have some insight.

Strangely, I did wonder if I could hear fluid rushing at one point.

Would this explain why it was so stiff to manipulate when disconnected from the rear arm? I seem to recall the front struts were a lot more moveable when I did the front arms with the suspension depressurised.

Any opinions on brand to buy? I have had a few bits from here in the past that seemed ok - https://aerosus.co.uk/land-rover/di...-rear-air-suspension-strut-left-or-right.html - they have a pair for £489 plus vat.

 

[Ubique]

They should be firm but move at a constant rate in either direction. The oil is there to provide the damping but also to lubricate the piston & ram, if the ram seal has failed, then there's a good chance of metal-on-metal noise once the oil has been pushed out.
BWI are the OE manufacturer, I've fitted Dunlop on the front of my Disco3, still working well six years later 'under new ownership' (i.e. one of my sons!)

The link doesn't mention a manufacturer but if you've had stuff before that you're happy with.... it's your car/money!

Maltings have the Dunlop ones listed slightly cheaper https://maltings4x4store.co.uk/susp...rut-for-discovery-3-and-discovery-4-lr038096/

 

[reb78]

Dunlop stuff has always been fine on the D2. I think they will do the job just fine. I find it harder with the D3 stuff to find named manufacturers - it was always a lot easier with the defender!

I'd be half tempted to just replace the shock itself but the bushes on the top of the air spring unit look really worn and I dont think they are available without the air spring?

I had heard BWI are the OE but the Dunlop ones save around £150 on those for a pair.

 

[Ubique]

Don't forget the airbag will have plenty of age-related cracks in it, it wouldn't be impossible to burst one due to 'assembly manipulation'.
We're changing about six Disco5 rear airbags a month, one, maybe two Disco3/4 in the same period. The Disco5's all have split airbags, the Disco 3's & 4's are generally damper failures.

 

[reb78]

Great. Thanks. I will do the whole unit, both sides with the Maltings ones you linked to. It doesnt look like a ridiculously long/complicated job having faffed about with it today? (although thats probably jinxed it now!)

Do the air connections just unbolt and then bolt into the new bag? I have never figured out how to put new connectors on the pipes. The D2 replacement bags were just push fits with a collar to remove.

 

[Ubique]

The air connections are probably the worst part of the job, brass fittings into plastic - very easy to get cross-threaded.
The way you're supposed to do it...
Unscrew VOSS connector from airbag, remove brass split collet, cut off ~6mm from end of pipe using single-sided razor blade (to remove the bit marked by the collet).
Replace airbag/damper assembly, pull out plastic locating pin from VOSS connector, making sure there are no burrs on the end of the airline, push into VOSS connector, twisting slightly to ensure the pipe hits the bottom of the seat.
IF this has been done before, the pipe may be too short so check there is enough slack first, if not, you'll have to refit the old VOSS connector to the new airbag. Get plenty of light around it so you can see if you're going in straight and some lube spray so the connector will rotate on the airline, that way you'll be able to feel if the threads are binding.

Oh, sounds obvious - make sure you lift it on the chassis, not the lower arms....

 

[reb78]

The air connections are probably the worst part of the job, brass fittings into plastic - very easy to get cross-threaded.
The way you're supposed to do it...
Unscrew VOSS connector from airbag, remove brass split collet, cut off ~6mm from end of pipe using single-sided razor blade (to remove the bit marked by the collet).
Replace airbag/damper assembly, pull out plastic locating pin from VOSS connector, making sure there are no burrs on the end of the airline, push into VOSS connector, twisting slightly to ensure the pipe hits the bottom of the seat.
IF this has been done before, the pipe may be too short so check there is enough slack first, if not, you'll have to refit the old VOSS connector to the new airbag. Get plenty of light around it so you can see if you're going in straight and some lube spray so the connector will rotate on the airline, that way you'll be able to feel if the threads are binding.

Oh, sounds obvious - make sure you lift it on the chassis, not the lower arms....

Thanks for that. I may cheat on that and re-use the old fittings rather than risk messing up fitting new ones. When I have looked at them before (when replacing valve blocks), I couldnt really figure out how reusing them would risk them failing and those ones didnt leak. I can test with soapy water afterwards.

I have the luxury of a ramp - I use a cross beam at the front across the wheels free beams with blocks to the chassis and put blocks under the chassis straight off of the beams at the back. They are quite close together so it will rock when on them if you arent careful (I am therefore careful!).

 

[Ubique]

The new VOSS connectors are already fitted, you just have to push the pipes in past the outer seal & the collet
If you've replaced valve blocks, then you'll be aware of the fragility of the threads in the plastic....
As I said, plenty of lube spray helps the fittings spin on the pipes.

 

[reb78]

The new VOSS connectors are already fitted, you just have to push the pipes in past the outer seal & the collet
If you've replaced valve blocks, then you'll be aware of the fragility of the threads in the plastic....
As I said, plenty of lube spray helps the fittings spin on the pipes.

Ah. I see!

I think with valve blocks, I unscrewed the new connectors, wondered what to do with them and screwed the old ones back in! But yes, what a pain

 

[minimutly]

Erm, any steel ball that doesn't run in nylon will creak if water gets through the boot. My Jaguar did it, fix was to replace the joint. I've heard discos making the exact same noise..

 

[reb78]

Erm, any steel ball that doesn't run in nylon will creak if water gets through the boot. My Jaguar did it, fix was to replace the joint. I've heard discos making the exact same noise..

Not sure it is one of the joints - as above, shock disconnected so the suspension could move without it and I couldn't recreate the sound.

 

[dave h 2]

Not sure it is one of the joints - as above, shock disconnected so the suspension could move without it and I couldn't recreate the sound.

I have never heard a shock creak knackered or otherwise, just liquid noises. Nor have I heard an unloaded suspension creak, put some weight on it and you get eeek - urkkkk.

 

[Bobupndown]

Are they the original rear struts / air bags still? If so you've done well for them to last 19 years.
D2 original rear air bags lasted 7 years for me and being so easy and cheap to replace i changed them after 4 years then.

 

[reb78]

Are they the original rear struts / air bags still? If so you've done well for them to last 19 years.
D2 original rear air bags lasted 7 years for me and being so easy and cheap to replace i changed them after 4 years then.

As far as I know they are. Certainly not been changed since I have owned it since 2018. So they are probably due replacement/likely to fail some time soon! D2 bags seem to do about 10 years or so in my hands so similar to you really. Moved to Dunlop from Contitech on those and the Dunlops have lasted better I think.

 

[reb78]

I have never heard a shock creak knackered or otherwise, just liquid noises. Nor have I heard an unloaded suspension creak, put some weight on it and you get eeek - urkkkk.

I get what you are saying, but with the wheel off, shock connected, I could hear the noise faintly as I manipulated the suspension up and down and it was most loud through my stethascope when it was placed at the top of the airbag/strut assembly, NOT over the bushes etc.

Shock disconnected (so still no load) and there was no noise from the suspension. I could not move the shock at all which i think was also odd - i.e. with a long bar under the shock, it was pretty solid!

 

[dave h 2]

In which case when you take the shock unit out just check the chassis mount hasn't cracked.