MK1 350i trailing arm suspension pin fitting?

[dw350i]

During the MOT, I found that one of the trailing arm attachment studs had worked very loose on the M12 side (chassis side), this was tightend up before leaving the testing station. 3 miles driven home, re-checked, the nut had loosened off slightly. The bushes look like they have been replaced not to long ago and the fitter had re-used the original nyloc nut. I have now replaced the nut with a new one, however, how tight are these nuts supposed to be and which part of the attachment is supposed to allow the arm to move on? Anybody know?

[adam quantrill]

Nothing 'swivels', it's the bush rubber itself that allows the rotation, so do it up tight (with the wheels on the ground).