Rear noise help....

[samcoombes]

Hi Guys

I'm at a loose end here. My 2004 3.0D is still making an intermittant rumble / groan / vibration from the rear.

• I occassionally tow a caravan and this makes it slightly worse, but it is there at all different times.
  More often than not around 40 mph
  If i floor it, the rumble is loud
  If I corner with a bit of speed, the vibration is bad, but it can vibrate a lot on a straight road too.

To date I have been to 3 garages (a tyre shop, a wheel balancing place and an Indy) and nobody can find anything.

It has recently had:

• All new tyres
  Hunter wheel alignment
  Full service
  Rear brake calipers stripped and cleaned (they thought it could be a sticky caliper)

Can anyone suggest anything? The vibration feels almost like the rear wheels are loose (they are not).

Thanks in anticipation.

[Upex]

Has anyone checked rear bearings, suspension, drive shafts and diff?

Where do you feel the wobble and what type of sound is it?

[X5Sport]

What tyres are fitted?  Do you have a 'square' or 'staggered' wheel size set up?

[themoog]

I would say wheel bearing if it does it when cornering. What about rear subframe bushes? One of our X5's makes a funny noise from the back (not mine..). Prop shaft? There's loads to check.

[moose04]

sounds like a universal joint, center bush or cv joint, for a piece of mind drop the rear diff oil, check the oil with a magnet see if there any metal bits, might be a diff bearing but i doubt this

[samcoombes]

Thanks guys.

The Indy said he had checked the drive train and the diff and it all looks / sounds / feels ok. He said the flex disc is good too.

Is it most noticeable around 40mph with my foot down, or when cornering at speed. Feels like the rear wheels are loose but they are not.

[Upex]

Has anyone checked rear bearings, and disks?

[samcoombes]

Has new discs and pads all round. Bearings have been checked only by wobbling the wheels off the ground. Is there a better check, as my mind is swaying towards these but I dont want to replace them without being sure. It's cost me nearly £1600 in 3 months!

[ianst0028]

let the air out of the suspension then wobble the wheel ..... the air springs take up a lot of slack

[themoog]

Yeah but not on the wheel bearings. Deflating the suspension will show up any loose joints at the back.

[ianst0028]

[quote="themoog"]
Yeah but not on the wheel bearings. Deflating the suspension will show up any loose joints at the back.

[/quote]

True..... I'd misread the previous post and thought that the bearings had been checked and were ok

[samcoombes]

Thanks guys - easiest way to deflate the suspension? And where should i place the axle stands to not effect the problem finding?!

[ianst0028]

i always put the stands under the jacking point on the sill
releasing the air is easy .... pull the relay or fuse for the air compressor and then release the pipe nuts on the black spheres in the boot

[samcoombes]

Thanks, will give it a go. Presumably it will reset itself or whatever?

[ianst0028]

yeah .... when youve finished tighten the nuts for the air suspension drop her off the jacks and put the relay / fuse in
turn on the engine and watch her rise