Front end drone - Partner HDi 2012

[AMacdonald]

Hi all.
I have a droning noise coming from my front end. It started gradually, is directly related to road speed, audible from about 20mph, and doesn't vary when turning. I've listened to the front bearings with a stethoscope (they don't sound rough) and swapped the tyres front to rear. No clicking or other CV-joint type noise. Nothing in the braking system gets unusually hot. All I can think of that remains is the gearbox final drive is wearing out. Have I missed anything obviously cheaper?

[mickthemaverick]

Presumably you listened to the front bearings with the wheel jacked off the ground? If so you are not getting a representative test because the wheel needs to be loaded and then spun at the appropriate speed. ?

[AMacdonald]

Yes. Jacking up the entire front end was the best I could manage and has shown up worn bearings in the past. The noise from worn bearings has always been noticeably reliant on steering angle and generally comes obviously from one side too. Is a representative bearing test even possible for the home mechanic?

[mickthemaverick]

Probably not, ideally you need a rolling road for the best testing situation. Because your drone is related to road speed the bearings have to be the most likely problem, however that's not to say you may have something else causing it such as wind noise through a crack in the bodywork or undershield. If you can make a video of it, upload it to Youtube and then post the link on here, someone may recognise the sound! Good luck

[AMacdonald]

I'll give that a go, although the recorded noise may well be drowned out by the racket a well used 2012 Partner generally makes.

[Paul-R]

Also, you said that turning the steering didn't affect the noise. I now suspect that you only turned the steering with the wheels suspended and then span the wheels. Which won't alter the load on the bearings.

What you need to do is drive the car and listen to hear if there's a difference as you go round a RH bend and then a LH bend. This will shift the weight of the car over to each side and, hopefully, you'll hear a difference which points to worn or damaged wheel bearings.

[AMacdonald]

All the observations (apart from the stethoscope to the hub - I'm not a lunatic/stuntman/Tom Cruise) have been done in motion. There is definitely no appreciable difference in the drone while cornering left or right.

[PaulC5]

Noises from worn gear box bearings can change if in different gears and when accelerating or slowing down. How many miles has it done, are there any oil leaks from the gear box ? There might be a bearing in the middle of a drive shaft to check.

[AMacdonald]

It's on about 160K. No leaks except what falls out whenever I disconnect a drive shaft (I did a gearbox oil change about 3 years ago) but the change has never been very slick. The drone doesn't change noticeably with gear or acceleration / deceleration.
Thanks

[moizeau]

Has your van got the intermediate/support bearing in the middle of the RH driveshaft?

[AMacdonald]

Good question. I haven't noticed one but I think I've only had the LH shaft out completely. I'll check that next chance I get, on wednesday. Thanks.