Odd rattle / squeal, something strange here

Very recently my MV has developed a strange loud rattle / squeal.

At idle there is no rattle/squeal, even blipping the throttle or engaging/disengaging the clutch.

Driving at low speeds there is a loud rattle, as if a piece of metal is rattling around. The rattle is not linked to engine revs as far as I can tell, nor does it go away with the clutch in or the gears in neutral.

Between 20 and 30mph the rattle noise goes away, but most of the time it is replaced by a loud squeal. The squeal goes away if I turn left but returns as soon as I straighten the steering wheel.

I have no idea what is causing it, I have prodded a few things but don't have the knowledge to track it down. anyone else got any ideas?

Could be a wheel bearing from the description you have given buddy.....

Gotta agree with Tim - wheel bearing !
Mine is doing exactly the same right now - bearing is ordered and will be fitted ASAP !

Darn!

One of the wheel bearings was noted as being 'slightly worn' during the MOT 5 days ago, to keep an eye on but nothing to worry about for now. THe bearing was replaced under 2 yrs ago so I thought it should be okay for a while ...

Oddly it is fine in reverse ... could take a while driving around though.

Almost definitely a wheel bearing although also worth checking the rear drums for binding/wear on the pads. You can replace the wheel bearings yourself if its the front that's gone. At the rear getting the driveshafts out of the rear hub is a bit*h, so you may well have to get a garage to do it for you. If doing the front bearings yourself make sure the faces of the hub where the bearings will sit are cleaned up and are completely square. The slightest misalignment caused by built up crud/grease will cause premature wear due to the bearing being under uneven load.

Cheers,

John

If not a rearing it could be the anti rollbar bushes as the speeds sound about right espesh if they happen on uneven or rough road surfaces hope this helps :D :D

I still can't be sure, I have a bearing on order, but later this week my friendly garage is going to test drive it after I have warmed it up to try and locte the problem. They gave it a quick drive (they are a bit busy) and said it could be the bearing or the rear brakes ... hard to tell can I bring it back later next week as there 20 capacity carpark is overflowing with jobs to be done.

Finally had some time to take it to the garage, after driving around with the mechanic hanging out the car with the door open, his opinion is it is not the wheel bearing but something to do with the main prop as the noise is coming from the centre.

UV joint? Or could it be a bearing?

It is being jacked up tomorrow for a better look. Hope it is not too expensive ...

Hmm... I get a metallic rattle when driving at low speed, e.g. in town or parking - please let me know the diagnosis!

It was jacked up and the problem was found to be the UV joint at the rear of the prop shaft, i.e. the one that fits into the rear diff. Apparently you could grab the shaft with your hand and give it a wiggle and hear it clank about in the rear diff. as the shaft is hollow, it transmitted the sound so it sounded like the clanking was coming from the front as you drove along with the windows down/door open. The UV joint that connects to the gearbox is fine. With hindsight, the rear diff seal ruptured a while ago and caused a small leak, so the rear diff was running low/dry for a while hence possibly the wear.

Either way the garage has found someone who sells UV repair/replacement kits for ~£50 for the main prop shaft on MVs. One should be arriving tomorrow, and the MV repaired next week.