Rear knocking noise, top mounts ?

[bmw9818]

Been hearing a rear end knocking noise over last few weeks, I replaced the rear mounts with apparently heavy duty mounts from eBay....

The car was tight when I first drove it after i lowered it around march last year, but it's now really soggy! When I have about 3 ppl in the back the car makes a really disturbing thump, the wheels arnt hitting or touching, but the people in the rear can feel the bump quite badly,

I bought the shocks and sprigs off the zone, apparently fronts are eibach, but no logo, rears are ta technix, it's only a 40mm drop but car looks too low,?

Any ideas

[mrLEE30]

three in the back woudl mean the thing is so low and the exhaust will be close to the trailing arms, my money is on this hitting. does it thump when no one in the back?

cheap springs can sag after use, or worse they can snap. yours could have done either.

soggy handling is more likey due to bushes

[bmw9818]

its not as loud when no ones in the back, but can still hear it, when going over a bump, not sure how long the guy had the springs before he flogged them onto me, but for a 40mm drop it looks pretty low! think i might invest in some eibachs, or any other reccomendations?

eibach springs and shocks? polybush the rear end and e46 cab top mounts, + a rear arb

[kam-325i]

check the rear beam bush's. When these fail, they can lower the back end by around 10mm

[Brianmoooore]

Have you fitted the load spreading washer on the rod of the rear dampers, under the top mounts. They last about a fortnight if these washers aren't fitted.

[bmw9818]

http://www.visionracingdevelopments.co. ... lted_l.jpg

This big washer resting on the mount? I copied the original setup, from the shocks i removed however after my dad came home there was a bit of uncertainty when he checked it....

I'm not 100% if I've done it like in the pic, I need to check tomorrow, I think I've got it the right sequence but it may be upside down, face down on the mount not curved up.....

[Brianmoooore]

That's the washer ABOVE the mount. I'm talking about the one that should be UNDER it.

[bmw9818]

Oh right, nah I don't think I did put one under there, the mounts just resting on top of the shock and I just tightened it on

[Jos]

You'll be needing a new set of top mounts then Is the damper is poking up through the mount?

[Brianmoooore]

You'll be needing a new set of top mounts then Is the damper is poking up through the mount?

That explains the knocking noise then!
How on earth do you think that little bush can take all the damping loads???

[bmw9818]

Yeah I done it in the same way as in the pic in link above, it's an encased shock so yeah I just dropped the mount on and bolted down

[loogie]

This explians why my top mounts have recently failed there is no bottom washer fitted! Is it the same shape and size as the top washer?

[bmw9818]

its a bit rounded like a dish, there available from bmw for a few quid,

[loogie]

Thank you will see if GSF sell them.