Disco 2 Noise from hear when coasting

Hi there, posting this here to get help

I have a noise coming from the rear that only appears when coasting - I recorded a video, hopefully people can hear it well:



Things I have already did myself:

- replaced front driveshaft with new one
- replaced rear driveshaft ujoints
- greased everything
- replaced rear left wheelhub

I then took the vehicle to a local so called "Land Rover specialist" mechanic - he removed the rear differential and said that under "visual inspection" did not detect anything unusual (but I don't think he knows how to inspect with proper gear marking compound for instance).

Does anybody have tips (or have suggestions) or what I should investigate next?

Thanks!

mcbrl said:

Hi there, posting this here to get help

I have a noise coming from the rear that only appears when coasting - I recorded a video, hopefully people can hear it well:



Things I have already did myself:

- replaced front driveshaft with new one
- replaced rear driveshaft ujoints
- greased everything
- replaced rear left wheelhub

I then took the vehicle to a local so called "Land Rover specialist" mechanic - he removed the rear differential and said that under "visual inspection" did not detect anything unusual (but I don't think he knows how to inspect with proper gear marking compound for instance).

Does anybody have tips (or have suggestions) or what I should investigate next?

Thanks!

Click to expand...

So he took it out when it was making that noise then put it back and it was still making the same noise?

By visual inspection I would hope he was testing for roughness, too much play in any of the components and the backlash between the pinion drive gear and the crown wheel, which from memory should be about 7 thou. He should also have checked for particles of metal in the diff casing and the oil when it was emptied.
To me it does sound as if it is worn as all the play will be taken up when accelerating but will show itself when coasting. Do you get the same under engine braking or does it go away again.

Thanks for the reply - the noise continues even when I press the brakes. But as soon I step on the gas, disappears.

I don't think he had tools to assess backslash up to that precision. There is no noticeable play when moving prop shaft manually (up/down) - nor when turning the wheels (prop shaft does move accordingly), without any play. And he did not find metal or particles (that's what I have been told at least).

Would driving around without the rear prop shaft (and diff lock engaged) help identifying the problem? I read on other forums people do this.

Also: how would you describe this noise? I am having trouble searching for similar problems on other forums / videos.

mcbrl said:

Thanks for the reply - the noise continues even when I press the brakes. But as soon I step on the gas, disappears.

I don't think he had tools to assess backslash up to that precision. There is no noticeable play when moving prop shaft manually (up/down) - nor when turning the wheels (prop shaft does move accordingly), without any play. And he did not find metal or particles (that's what I have been told at least).

Would driving around without the rear prop shaft (and diff lock engaged) help identifying the problem? I read on other forums people do this.

Also: how would you describe this noise? I am having trouble searching for similar problems on other forums / videos.

Click to expand...

Pressing the brakes would have the same effect as acceleration, which is why I asked about engine braking, i.e. using low gear to slow the car down on a hill but not using the brakes.
So if it continues when pressing them, in neutral, we may have to look elsewhere. i had a bad rumble and vibration comeing from mine on my D1 and it turned out to be that the mech who changed the diff simply hadn't done the pinion nut (or bolt I forget which it is) up tight enough. But I couldn't tell the play until I undid the rear propshaft and took it down away from the diff, then I could feel all sorts of play in the flange.

You might as well drop the prop and do as you say. You are lucky to have diff lock in a D2 lots of us haven't!

I'd consider looking at the handbrake drum etc too and also the other hub.

Best of luck with it.

And welcome to the forum by the way!!

(There is an "Introduce yourself" bit for when you have the time!)

Stanleysteamer said:

Pressing the brakes would have the same effect as acceleration, which is why I asked about engine braking, i.e. using low gear to slow the car down on a hill but not using the brakes.
So if it continues when pressing them, in neutral, we may have to look elsewhere. i had a bad rumble and vibration comeing from mine on my D1 and it turned out to be that the mech who changed the diff simply hadn't done the pinion nut (or bolt I forget which it is) up tight enough. But I couldn't tell the play until I undid the rear propshaft and took it down away from the diff, then I could feel all sorts of play in the flange.

Click to expand...

Ah sorry, did not know the term engine braking.

Yes I tried going downhill without pressing the gas pedal (nor brakes) - the noise is still there. As soon as I touch the gas, noise goes away. I tried in neutral as well as engaged in D, or 3, 2, 1 (1 less prominent given the lower speed).

And I cannot feel any play on the diff flange / and the outside pinion that is sticking out of the diff (trying to move by hand of course).

Stanleysteamer said:

You might as well drop the prop and do as you say. You are lucky to have diff lock in a D2 lots of us haven't!

Click to expand...

Yep, I will try that now.

Stanleysteamer said:

I'd consider looking at the handbrake drum etc too and also the other hub.

Click to expand...

Any particular tip on what to look for at the drum? When I remove the prop shaft, the drum has some play (but I guess the four bolts from the prop shaft are the ones that hold it in place).

Stanleysteamer said:

Best of luck with it.

And welcome to the forum by the way!!

(There is an "Introduce yourself" bit for when you have the time!)

Click to expand...

Thanks! Yep, I will do that soon

Cheers

mcbrl said:

Ah sorry, did not know the term engine braking.

Yes I tried going downhill without pressing the gas pedal (nor brakes) - the noise is still there. As soon as I touch the gas, noise goes away. I tried in neutral as well as engaged in D, or 3, 2, 1 (1 less prominent given the lower speed).

And I cannot feel any play on the diff flange / and the outside pinion that is sticking out of the diff (trying to move by hand of course).

Yep, I will try that now.


Any particular tip on what to look for at the drum? When I remove the prop shaft, the drum has some play (but I guess the four bolts from the prop shaft are the ones that hold it in place).



Thanks! Yep, I will do that soon

Cheers

Click to expand...

As for the hand brake drum, TBH you may have to dismantle it and look at it. Drop the prop, put the handbrake on then there is one cross head screw which you may need an impact driver to release. Then you can let the handbrake off and pull the drum away. If a spring has broken it should be obvious.
Have you tried jacking up the other rear wheel and spinning it, listening for bearing rumble and feeling for play?

I'm much less convinced it is the diff now.

mcbrl said:

Also: how would you describe this noise? I am having trouble searching for similar problems on other forums / videos.

Click to expand...

I'd describe it as a light whirring noise. It's quite high pitched but not a "scream". It seems to be consistent with road speed, would you agree with that? In which case it could be worn hub bearings or diff bearings, (according to my Haynes manual!) which isn't the Bible.
So if the mech who looked at the diff is any good that should narrow it down to hub bearing.

I have changed three of the hubs on mine and not in one of them could I feel the play. In two the ABS etc lights came on and in the other, a front hub, it just made a consistent noise, not as loud as yours, my wife couldn't hear it. My other hub is now making the noise but I have yet to change it. The only surprising thing is that if the hub is worn usually the "three amigos" lights come on (ABS, Hill Descent Control, Traction control) but in the case of my front hub they didn't so it isn't cast iron guaranteed.