[Mango1991]

Has anyone ever had to replace the rack on their e92 lci
Had my car at bmw specialist and they spent half a day checking over ever nut and bolt on the suspension also all the bushes etc. this problem originally started after fitting poly bushed radius arms and m3 control arms everything has all been tightened on four poster with the load of car on all bolts. When I put the original arms back on the noise is still their just not as bad think the harder bushes amplify the noise. The bmw specialist said they think it is the steering rack that’s knocking I replaced the rack with a second hand 1 before taking it to specialist but they still say it’s the rack and that’s the 1st thing they would replace with a new 1. Any ideas please

[juld0zer]

What scenario(s) does the knock occur? Going over straight and sharp surfaces such as a join in the road or near a bridge? That's the M3 arms. You can fit either the tension struts/upper arms only (changes the caster slightly) or the lower arms only (gives the extra negative camber).

When installed together with an unreinforced subframe, you get a very strong crashing sensation because the tension strut bush is solid rubber and the lower wishbones eliminate the stock rubber bush at the subframe end, replacing it with a balljoint that transfers all the harshness previously dampened by the rubber bush. This is a debatable topic and some swear by the genuine BMW arms and claim the TRW ones are more noise prone.

On my 135i i put the stock lower arms in and the car was like stock with M3 (TRW) tension struts
On my 130i i was hesitant to do it but I installed the M3 (TRW) lower arms with stock tension struts and it also feels like stock going over the same ruts. If I had to pick one arm, it would be the lower arms. The steering has a night and day different (better) feel.