Mild howl from tyres or other problems?

[V2Evo96]

Getting a mild howling sound from somewhere when I decel to a stop or roundabout in the 2009 4L D3 (83,000 on the clock).

Don't notice it at speed or when accelerating (could be there but can't hear it) - only very noticeable when slowing down. It starts around 65/70kmh when either braking or rolling to slower speed. I've put the tranny in N while it happens and there is no change to the sound. I've pressed the brake pedal hard when it happens (as a test) and it does reduce a bit only while the brake is on.

The Kuhmo tyres have about 10,000k's left on them and I'm wondering if these could be the culprit although this just started a week ago(well I'm hoping it's tyres rather than drivetrain issues!)

Has anyone experienced this issue and if so any ideas on what could be the cause?

Thanks in advance for any assistance.

[sheerluck]

What variety of Khumos have you got on there? Is there any noticeable variation in wear across the width of the tyres?

[V2Evo96]

What variety of Khumos have you got on there? Is there any noticeable variation in wear across the width of the tyres?

Thanks sheerluck,

Kuhmo's are Road Venture APT OEM 18" wheels. Tread wear nice and even across the width, alignment and rotate done about 5000k's ago - no noise then .

[sheerluck]

Have you had the diff oils changed? What about an auto tranny service?

[V2Evo96]

Auto tranny fluid changed at 62,000, diff and transfer case fluids will be changed next week. Vehicle over-maintained by previous owner to satisfy the extended warranty requirements (not extended LR warranty as I recall without looking at it it's by AWM).

If it is driveline, any idea what it could be? COuld be a 'lash' issue somewhere? Worse? I feel ill.....

[sheerluck]

It's very difficult to give a clear diagnosis in these circumstances, but I have heard of several cases where the tyre noise worsened as the tyres wore.

However, there have been multiple cases of diffs becoming very noisy too (though that shouldn't come on suddenly)

I'd put a request out to see if you can swap tyres with someone to eliminate that first, then go ahead and do a diff oil change. It wouldn't hurt and is pretty cheap if you do end up changing diffs.

[vnx205]

While not exactly the same situation, there may be some connection between your experience and mine.

I used to run Jeep Service retreads on my Series III. They were never noticeably noisy except when I swapped the front tyres to the back and vice versa. For a short time, they howled enough to hear above the usual noises a Series LR makes.

The tread used to wear a saw tooth pattern. The front was in the opposite direction to the rear. Swapping the tyres briefly left the saw tooth facing the opposite way to the way it would eventually wear.

Is it possible that your tread has a slight saw tooth wear pattern created by the tyres driving the vehicle forward most of the time? If so then when the vehicle is decelerating, the saw tooth would effectively be the opposite way to the way it naturally wears.

Anyway while you consider that possibility, it might take your mind off the possibility of some more serious and expensive cause.

[V2Evo96]

Thanks sheerluck - It DID start very quickly - like one day quiet as usual then the howl started and no change of pitch or volume since it started (a week ago).

Big Thanks - I won't be able to swap the tyres with anyone, but as they are pretty much on the way out I may change them for new anyway. Gotta get them sooner or later....

[V2Evo96]

VNX I hope you are right!

While not exactly the same situation, there may be some connection between your experience and mine.

I used to run Jeep Service retreads on my Series III. They were never noticeably noisy except when I swapped the front tyres to the back and vice versa. For a short time, they howled enough to hear above the usual noises a Series LR makes.

The tread used to wear a saw tooth pattern. The front was in the opposite direction to the rear. Swapping the tyres briefly left the saw tooth facing the opposite way to the way it would eventually wear.

Is it possible that your tread has a slight saw tooth wear pattern created by the tyres driving the vehicle forward most of the time? If so then when the vehicle is decelerating, the saw tooth would effectively be the opposite way to the way it naturally wears.

Anyway while you consider that possibility, it might take your mind off the possibility of some more serious and expensive cause.

[Epic pooh]

Diffs can make a range of noises. My last diff made noises under acceleration / light loads (but a range of other noises are possible depending on worn component). Mine started making a distinctive noise quite suddenly and I successfully ignored it for a year before the wife decreed "get it fixed".

Diff wasn't particularly shockingly expensive ($1600 by dealer). Other howling things can be wheel bearings (normally related to road speed). The only howling / growling thing I've experienced over the years on decel is my ac compressor ... Which I am currently trying to ignore as that is about as expensive as the diff to change ... Oh well such is disco life

As sheerluck says, proceed with the oil change and see how it pans out - some noises are best left to develop so they can be clearly diagnosed and this might be one of those. See what your spanner spinner thinks when the oils are being done. And good luck !