regular thrumming noise barely audible, coming from transmission and or running gear.

Hi gang!
the noise is a low regular thrum...thrum...thrum. Each noise lasts about 1/2 a second and doesn't seem linked to what gear I am in, (auto anyway)
Any ideas please?
I suspect CV joint or one of the props U/Js but would like to know if there are any obvious things to check before I start jacking it up and taking things of to test them.
It sounds a bit more when cornering and doesn't make any difference whether turning to the left or the right. This all happens at low to medium speeds. Not tried going any faster than 90kph.
But it doesn't make the graunching sound on full lock that I have heard before from CV joints. The bellows are all fine as far as I can tell, though I know this may be insignificant.

And can anyone tell me if there is a clever way of testing the CV joints, please?
On a two wheel drive car I'd know what to do!

Next plan is to jack it up, put it on stands and feel for movement in the U/Js.
Any advice would be most gratefully received.
Thanks in advance.
Stan.

I had something like that on mine, happened around 40-50ish mph. I'd already decided to put a new front prop on with proper grease points and put a new rubber ring on the rear prop whilst changing a slightly weepy diff seal. The noise never appeared again. Front prop was OK, I just wasn't happy with the lack of grease points to keep me busy but the rubber ring on the rear was starting to show signs of ageing.

Feathers McGraw said:

I had something like that on mine, happened around 40-50ish mph. I'd already decided to put a new front prop on with proper grease points and put a new rubber ring on the rear prop whilst changing a slightly weepy diff seal. The noise never appeared again. Front prop was OK, I just wasn't happy with the lack of grease points to keep me busy but the rubber ring on the rear was starting to show signs of ageing.

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Cheers mate, I'll check both of these.
I've changed the donut before on a D1 but the fancy front prop is new to me and knowing its rep.....
especially without proper grease points.....
I'll let yo know progress as I make it, IF I make it!

Feathers McGraw said:

I had something like that on mine, happened around 40-50ish mph. I'd already decided to put a new front prop on with proper grease points and put a new rubber ring on the rear prop whilst changing a slightly weepy diff seal. The noise never appeared again. Front prop was OK, I just wasn't happy with the lack of grease points to keep me busy but the rubber ring on the rear was starting to show signs of ageing.

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Just checked both props today and their attachments. nothing seems to be wrong there.

Stanleysteamer said:

Just checked both props today and their attachments. nothing seems to be wrong there.

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Well that's a fair bit ruled out. Is the thrumming at a propshaft or road-wheel rate? Does it seem to be coming from the front or rear?

I assume the items that should contain oil, axles, TB etc have their normal quantity?

PopPops said:

Well that's a fair bit ruled out. Is the thrumming at a propshaft or road-wheel rate? Does it seem to be coming from the front or rear?

I assume the items that should contain oil, axles, TB etc have their normal quantity?

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Hi @PopPops
I'd love to be able to tell you the rate at which it is occurring, but I can't swear to which it is. Prop shaft would obviously be faster, that I get. Sorry to be so hopeless on this.
As for from which end, in order to do this i would have to get Wifey to drive the car while I cavort inside the car from one end to another to listen with an ear to the floor.
This even she managed to suggest after I asked her to do it, and she said she wouldn't. To be fair, she says she can't hear it.
So that is on the cards, for soon.
I also today jacked up each road-wheel in turn and tested for bearing wear. The rears were absolutely solid and the fronts solid in the vertical plane and with only the tiniest of movement in the horizontal plane. So I felt for movement at the UJ and there seemed to be a tiny bit, both sides. I didn't feel this was abnormal. Maybe it wasn't. But I can't feel any torsional play on them.
And yes all fluid levels are up to the level, didn't need topping up at all. Except for the autobox which is an ongoing situation as it has a small leak, so I top it up regularly until I can get back to the UK where I have finally found a bloke willing to take the box of and tighten the bolts/ do any seals or gaskets needed. TBH I didn't even check the front axle as there are no signs of leakage whatsoever anywhere since I last checked it, when, A, it didn't need topping up and, B, there were no signs of leakage then.
However, this is a bit of laziness I will conquer and check it too.
At the moment I am leaning to toward it being one of the joints on the front prop, purely because I know they are prone to going and also although I have tested it, I have only done this on the car, so I will take it off and give it a thorough going over.
TBH I wish it was a bit worse as then it would be more obvious.
We have family coming next week for a week or so, so I will not be doing much on it between now and then end of that week. But we wont be driving it when they are here as there will be six of us and our D2 only has seats for 5.
If I still fail to find it I'll have to take it to a 2local" LR bloke to look at . Problem being he is 20 miles away and we have no 2nd car. Will have to prevail on friends and neighbours or else hire a car. Leclerc do them quite cheap, i have heard, charging you very little per day and making the money on the mileage, which would suit us as we don't go out and about much!
But thank you very much for your interest and if anything else occurs to you I am sure you will post it.
All the best.
Stan

Good luck and keep listening for it. I was cleaning brakes and wiggling wheels and joints for a while until I did the rear diff oil seal.

How are your tyres? Sometimes they get noisy as they wear

Kev12 said:

How are your tyres? Sometimes they get noisy as they wear

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Thanks for this.
They are fine, quite a new set of BFG A/Ts.

Feathers McGraw said:

Good luck and keep listening for it. I was cleaning brakes and wiggling wheels and joints for a while until I did the rear diff oil seal.

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After you mentioned this, I looked at mine and it seems to be OK and, as I said, the level hadn't dropped.
In your case did it drop sufficient to cause the noise then?
On a D1 I did have some awful vibration which in the end turned out to be that the pinion nut had somehow worked loose..
Took it all apart, with all the necessary effort and tightened it. (no seal were weeping at all.) Noise and vibration went completely away. But this doesn't feel like it at all, and also in that case there was obvious play at the diff flange.

Stanleysteamer said:

After you mentioned this, I looked at mine and it seems to be OK and, as I said, the level hadn't dropped.
In your case did it drop sufficient to cause the noise then?
On a D1 I did have some awful vibration which in the end turned out to be that the pinion nut had somehow worked loose..
Took it all apart, with all the necessary effort and tightened it. (no seal were weeping at all.) Noise and vibration went completely away. But this doesn't feel like it at all, and also in that case there was obvious play at the diff flange.

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Nothing made any difference until one week I put a new prop on with the extra grease points on the front joint (you can get the bits to do it yourself but at that time I didn't want the risk of a job taking longer than expected) and I changed the rear diff seal and realised the doughnut was showing signs of hardening and replaced that. Been fine ever since. BTW, the front prop joints felt fine with no tight spots or any signs of wear, I just felt more comfortable with that front bit having grease points like the other joints hence the upgrade.

Feathers McGraw said:

Nothing made any difference until one week I put a new prop on with the extra grease points on the front joint (you can get the bits to do it yourself but at that time I didn't want the risk of a job taking longer than expected) and I changed the rear diff seal and realised the doughnut was showing signs of hardening and replaced that. Been fine ever since. BTW, the front prop joints felt fine with no tight spots or any signs of wear, I just felt more comfortable with that front bit having grease points like the other joints hence the upgrade.

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Would you mind telling me where you got it from (front prop)as I would also like to be able to grease it properly!
I suppose I could feck about drilling holes and tapping them what is it, 2BA? but think I'm getting a bit too fed up of all this now.

Stanleysteamer said:

Would you mind telling me where you got it from (front prop)as I would also like to be able to grease it properly!
I suppose I could feck about drilling holes and tapping them what is it, 2BA? but think I'm getting a bit too fed up of all this now.

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JGS4x4 heavy duty front prop. I certainly wouldn't try drilling and tapping one, I know my limits!

Feathers McGraw said:

JGS4x4 heavy duty front prop. I certainly wouldn't try drilling and tapping one, I know my limits!

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Thanks for that!
If I was back in the UK I might try, but my 2BA tap is back there and I'd also need to find either another grease nipple or a plug with a 2BA thread on it. Not easy in Frogland. Could i suppose hunt down a Frog grease nipple, but my interest in this is fading. I do have metric taps and dies here, though.
Cheers again. Still won't have time to even take the thing off just yet what with family coming and all!

Update on all this.
Still have the thrumming.
But have been pming another LZ peep who runs a garage, and following his suggestions.
As I thought and he thinks too, it doesn't seem to be hubs or brakes.
But the Hooke joint on the front prop is a teeny weeny bit loose and there is a rumbling coming from the rear of the transfer box once I have disconnected both props and run it in drive, while I use the old screwdriver stethoscope trick.
Bad news is the nearest LR garage no longer is one. But the guy still stocks secondhand parts. Been on hol this week but tomoz he'll be back so I'll give him a ring and see what he has got.
Watch this space!

Latest news, bought a second-hand front prop from him and also a second-hand hub.
Fitted the prop today have yet to test it properly.
Will let you know if it is any better.

Right, now folks!
News!
re the "thrum...thrum...thrum" my blessed Disco makes.
I changed the front prop yessdi, test drove it, no difference.
So I decided yet again to give the wheels another good looking over, starting with the one that is leaking oil. (Nearside rear)
So I stripped it down bit by bit and discovered that the oil seems to be coming from the sensor hole.
So I cleaned it a bit and gave it a wee tweek It hardly moved.
So then concentrated on cleaning it further, and found .....(Roll of drums!).....GREASE!
Aha! I sez to meself! Now how the feck has that got out of the bearing?
So I stopped before going ahead and taking it off, thinking i'd talk to you peeps.
I a\m wondering if the bearing is partially seized and has heated up and chucked a load of grease out. Although when it first became obvious to me I went around and touched all the wheel hubs to see if any were hotter than any other, and none were.
There are no leaks on any of the other three hubs and i had to take the two front ones off to put new boots on the big ball joints there, so I know i have tightened them up to spec and they would all be as clean as they should be. (I'm meticulous over cleanliness, lubrication and torqueing up nuts and bolts.)
So now I am left wonderin if I should jack up the other side and check it out too before going any further, or whether I should go ahead and take the hub off?
Like many others on here I am very loath to play with removing the sensor from a hub cos of all the probs peeps have had with them once off and then back on again.
But the good one back in the UK still has its sensor attached, and between now and getting back I don't give a fig for HDC, TC or ABS.
So, all you peeps with all the experience, what do you think?
Answers in the usual fashion please!
Stan.

Stanleysteamer said:

Right, now folks!
News!
re the "thrum...thrum...thrum" my blessed Disco makes.
I changed the front prop yessdi, test drove it, no difference.
So I decided yet again to give the wheels another good looking over, starting with the one that is leaking oil. (Nearside rear)
So I stripped it down bit by bit and discovered that the oil seems to be coming from the sensor hole.
So I cleaned it a bit and gave it a wee tweek It hardly moved.
So then concentrated on cleaning it further, and found .....(Roll of drums!).....GREASE!
Aha! I sez to meself! Now how the feck has that got out of the bearing?
So I stopped before going ahead and taking it off, thinking i'd talk to you peeps.
I a\m wondering if the bearing is partially seized and has heated up and chucked a load of grease out. Although when it first became obvious to me I went around and touched all the wheel hubs to see if any were hotter than any other, and none were.
There are no leaks on any of the other three hubs and i had to take the two front ones off to put new boots on the big ball joints there, so I know i have tightened them up to spec and they would all be as clean as they should be. (I'm meticulous over cleanliness, lubrication and torqueing up nuts and bolts.)
So now I am left wonderin if I should jack up the other side and check it out too before going any further, or whether I should go ahead and take the hub off?
Like many others on here I am very loath to play with removing the sensor from a hub cos of all the probs peeps have had with them once off and then back on again.
But the good one back in the UK still has its sensor attached, and between now and getting back I don't give a fig for HDC, TC or ABS.
So, all you peeps with all the experience, what do you think?
Answers in the usual fashion please!
Stan.

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Hi Stan, mine with it's knackered osf wheel bearing, makes a similar noise & vibrates through the throttle pedal/cabin but what I did notice is when going round bends at 20/30/40 mph, which loads that side all the vibrations disappear & like you when it started making that noise I kept checking the wheel to see if got any warmer than the rest but it didn't. As the bearings are zz (metal shields)as opposed to rs (rubber seals) if there is play in your bearing & it's running warmer then the grease could well come out easier of the metal shields.
Hope it's a straightforward fix like I'm hoping mine will be, when my hub eventually gets here. Best of luck.

Andy Warren said:

Hi Stan, mine with it's knackered osf wheel bearing, makes a similar noise & vibrates through the throttle pedal/cabin but what I did notice is when going round bends at 20/30/40 mph, which loads that side all the vibrations disappear & like you when it started making that noise I kept checking the wheel to see if got any warmer than the rest but it didn't. As the bearings are zz (metal shields)as opposed to rs (rubber seals) if there is play in your bearing & it's running warmer then the grease could well come out easier of the metal shields.
Hope it's a straightforward fix like I'm hoping mine will be, when my hub eventually gets here. Best of luck.

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Hi Andy!
What you say makes a lot of sense, and yes it does seem to go away a bit on turns.
What you say about metal as opposed to rubber shields/seals also makes sense.
So, if this is the problem, and I solve it with the second hand, but Timken, bearing in the hub flogged to me by the Dutch guy, he will be getting a very nice phone call.
It would appear he is right about after market bearings and once this is solved, if it is solved, I'll go back and find who I got it from and warn everyone.
What make/supplier of bearing are you getting? If I dare ask!
Thanks massively for the support and encouragement!

Stanleysteamer said:

Hi Andy!
What you say makes a lot of sense, and yes it does seem to go away a bit on turns.
What you say about metal as opposed to rubber shields/seals also makes sense.
So, if this is the problem, and I solve it with the second hand, but Timken, bearing in the hub flogged to me by the Dutch guy, he will be getting a very nice phone call.
It would appear he is right about after market bearings and once this is solved, if it is solved, I'll go back and find who I got it from and warn everyone.
What make/supplier of bearing are you getting? If I dare ask!
Thanks massively for the support and encouragement!

Click to expand...

I ordered the Optimal hub 'kit' last Monday so when I get it I'll see what make of bearing is fitted & let you know. I didn't think the noise I had could be a wheel bearing at first especially with the harsh vibration through the throttle pedal but when I noticed the noise/vibration disappeared when I cornered, I jacked it up & sure enough a fair bit of play. It's the opposite side to the drive shaft oil seal I did (with your great tip of taking the d/shaft & hub out in one) but this time I'll have to undo THAT nut to change the hub . I going to change the seal & knuckle ball joints whilst it's apart, in for a penny in for a pound, so with the new hub I hope I won't have to revisit that area for some time.
When do you hope to tackle yours ?