In Reply to: replacing control arms / bushings / steering rack posted by matthew on January 27, 2000 at 07:49:03:
The e34 front suspension setup basically consists of the control and thrust arms with the struts and anti-roll bar.
The control arm is the lower front piece and this arm maintains the track of the wheels with respect to the car.
The thrust arm is the upper rear piece and this arm takes up the load of the car during braking forces and it also assists to hold the wheel in place and also make up a part of the geometry of the steering system.
Both the arms has ball joints on one end and bushings on the other.The ball joints are attached to the wheel side.
The e34 does not employ the steering rack and pinion system but uses the recirculating ball type of steering system.Wear and tear in this steering box could lead to some "play" in the steering wheel.The slack can be minor ajusted by tightening the screw on the steering box.
On the e34,the linkage from the steering box to the wheels are called the tie rods and consists of three 'links' ie. center tie rod (1x),tie rods (2x),and tie rod ends(2x).Another part of the system is the idler arm which is connected to the pax side of the center tie rod,which helps to hold the tie rods together.At the ends of the rods are ball joints,which if worn,will give the tramlining effect or the vague/sloppy feeling of the steering.
E-mail me for more info.
moots '90 520i- tight steering and suspension
: i have a 76k 1994 525iSE with 17" rims and 235/45 tyres
: i have reviewed many helpful pages from this site dealing with how to lessen the effects of tramlining/shimmying. there have been a few contradictory responses, though
: the suggested remedy appears to be replacement of the lower control arms and bushings. are "control arms" different to the "thrust arms"?
: what about the steering rack? i thought that was an entirely different component but does that also need to be replaced to ease tramlining?
: and how do "tie rods" fit into all this?
: i have a basic knowledge of the steering/suspension components and so i really need someone please to explain what exactly it is suggested should be replaced (and why) and how best to explain to the mechanic what is needed