Clunky rear end

bigendbob · Post by **bigendbob** » Mon Jul 30, 2012 9:54 pm

Hi guys new here.
Have had for last 6 weeks 2009 plate 23i Orion silver 30k miles bought from BMW garage. Before i go back to them anyone experienced any clunking from the rear axle area.
Nothing heard on acceleration/deceleration, only on first turn say left theres a clunk, then ok if i keep turning left, then when i turn right theres another clunk then nothing till i turn left again.
Almost like something loose in the boot, but the boot is empty?
I noticed at one junction when i came to stop where the road was a bit rough, so the brake pads were under load and therefore not free to float, again a similiar clunk but 2 or 3 times, almost as the suspension bounced.
First impression some kind of worn bush or the diff wobbling about loose.
Anyone any ideas?

Zed Five · Post by **Zed Five** » Mon Jul 30, 2012 10:01 pm

Check under the boot floor in the battery compartment? Worth a look.

TitanTim · Post by **TitanTim** » Mon Jul 30, 2012 10:02 pm

Similar discussion on ZPost,

http://e89.zpost.com/forums/showthread. ... 821&page=2

Tim.

bigendbob · Post by **bigendbob** » Mon Jul 30, 2012 10:30 pm

First time i've had a car with some kind of warranty.
Always done my own repairs so in no hurry to dash off to the dealer and find the car comes back worse.
Have got access to a ramp so will have to investigate further, just looking for some leads or known issues. The car i was told was first bought on launch so one of the first.
Had similiar problem with a MGTF, that was worn tie rod ends, and that at 30k.
ps the battery is rock solid and so is the hood mechanism.

Maniac · Post by **Maniac** » Tue Jul 31, 2012 7:11 am

Oddly I used to have the same noise at full extension of the rear suspension ( say going over a hump at speed ) or when crossing a hump or uneven surface diagonally. However since jacking the car up to change tyres the noise has gone. I suspected either a mal seated spring or anti roll bar. Similar again to the e89 forum thread above. It's gone now so I guess whatever was at issue it's now reseated.

bigendbob · Post by **bigendbob** » Tue Jul 31, 2012 10:10 am

Begining to wonder if its the brake calipers floating seeing as though they are probably quite heavy with the motor. A normal handbrake would have a cable that dampens out any movement. On these when the pad retracts it might give quite a clearance between pad and disc thus allowing them to bang againt the disc.
Think i will jack up with brake off and give em a waggle. At worst change pads and see what happens.

Maniac · Post by **Maniac** » Tue Jul 31, 2012 10:22 am

I'd be interested to hear what you discover..

bigendbob · Post by **bigendbob** » Tue Aug 07, 2012 9:45 pm

Well today got fed up of the noise, went to local dealer where i was told it would cost me £100 for them to investigate, if found not to be approved warranty fault.

So i jacked up the vehicle and had a look. Within a minute i grasped a drive shaft to the right wheel and it would slide laterally along its length about 3/4 inch and bang one way against wheel hub then bang the other way against inside of the differential!
I've never come across a design like this before, usually one end or both are tied via a cv joint. This seems to use a splined joint each end which is free to float and bang at either end.

The noise sounds right.
Then went for a test run. Drove car and then i swerved or s turned, this seemed to centre the shafts so no noise at speed in a straight line and turning at speed. But when i slowed down to turn through 90 degrees such as normal junction a knock would occur, then on next opposite turn another knock. I think the difference in wheel rotation is throwing one or other shaft against the wheel hub or diff. The car as done 30k, the shaft gaiters seem very thin. I wonder if now they have become soft through wear they used to act as dampers but now allow the shafts to float and bang.

I can see me having a fight to get these fixed under warranty.

Maniac · Post by **Maniac** » Wed Aug 08, 2012 11:23 pm

bigendbob wrote: I can see me having a fight to get these fixed under warranty.

Especially if it's not a fault and it's just the way they are. I don't get this sort of noise when turning, just a knock from the rear occasionally over bumps like sunken manhole covers.

bigendbob · Post by **bigendbob** » Wed Aug 08, 2012 11:44 pm

Well had it up on a ramp today and sat in whilst garage owner moved the shafts. Definitly the sound i hear when driving. Got it booked in Monday at BMW.
Either they are faulty, a bad design or worn.
If no joy with BMW wiil probably go down the root of trying to inject more grease through a temporary hole in gaiters and seal up with super glue.
Can't put up with a car of this so called quality having knocking drive shafts. What will be the long term damage?

bigendbob · Post by **bigendbob** » Thu Aug 16, 2012 6:38 am

On going saga here
http://e89.zpost.com/forums/showthread. ... st12512298
If mods don't mind.

bigendbob · Post by **bigendbob** » Fri Aug 17, 2012 5:39 pm

Might have found it!
Rear subframe mount disintegrating, in the right place to make the noise, the metallic parts are only 3-4 mm's apart. Will post a pic when i find out how to.

Everyone out that check those rubber bushes.

TitanTim · Post by **TitanTim** » Fri Aug 17, 2012 5:47 pm

bigendbob wrote:Might have found it!
Rear subframe mount disintegrating, in the right place to make the noise, the metallic parts are only 3-4 mm's apart. Will post a pic when i find out how to.

Everyone out that check those rubber bushes.

Would expect bushes to last 60 to 70k before requiring replacement so might be worth badgering BMW for some goodwill but bushes will wear out sooner or later.

Tim.

bigendbob · Post by **bigendbob** » Fri Aug 17, 2012 6:01 pm

Not at 30 k though.
Will visually check all four before approaching B'em dealer and try and get all four replaced while under warranty.
First thing they can do is give back the £45 they had off me for the first look they did.

AlanJ · Post by **AlanJ** » Fri Aug 17, 2012 6:07 pm

bigendbob wrote: Will post a pic when i find out how to.

http://www.z4-forum.com/forum/viewtopic.php?f=11&t=30

Z4-forum.com

Z4-forum.com

Clunky rear end

Clunky rear end

Re: Clunky rear end

Re: Clunky rear end

Re: Clunky rear end

Re: Clunky rear end

Re: Clunky rear end

Re: Clunky rear end

Re: Clunky rear end

Re: Clunky rear end

Re: Clunky rear end

Re: Clunky rear end

Re: Clunky rear end

Re: Clunky rear end

Re: Clunky rear end

Re: Clunky rear end