Steering

Want to go round a corner? Then you're going to need some Steering.

Overview

Every E30 came with a Rack & Pinion steering configuration, which is a simple configuration found in most cars. The pinion gear sits on the end of the steering column/shaft which has the steering wheel at the other end. As you turn the steering wheel, the pinion gear then turns which moves the rack laterally, causing the track rods to push or pull the wheels, allowing the car to turn.

Simply put, the rack and pinion does two things; it converts the rotational motion of the steering wheel into the linear motion needed to turn the wheels, and it provides a gear reduction making it easier to turn the wheels.

The E30 came with either Power Assisted Steering or non-Power Assisted Steering. PAS uses a hydraulic pump powered by a pulley driven via a belt attached to the crank pulley. This fluid drives a piston built into the rack to make it easier to turn the pinion gear.

Components

Rack

Simple overview of Rack & Pinion Steering

As mentioned earlier, there is a PAS and non-PAS rack available for the E30. Both forms are generally very reliable.

Tie Rods

The tie rod is what connects the rack to the wheel hub. At the rack end the tie rod simply screws into the output shafts of the rack, there is an inner and outer ball joint as you can see in the below image. The tie rod itself can be split in two leaving you with the outer part commonly known as the track rod end. The amount this is wound back into the tie rod is what affects the front wheel alignment. The inner ball joint is protected by the rubber gators which fit over the end of the rack and then onto the rubber grommit you can see part way down the inner section of the track rod.

Complete E30 Tie Rod.

PAS Pump

The PAS pump is located on the front left hand side of the engine, it take the PAS fluid down from the resivoir and then pumps it under pressure to the rack when the steeing wheel is moved, this process makes the weight of the steering much lighter for the driver.The PAS pump is driven by an auxillary belt so as the belt wears or become stretched the effectiveness of the pump decreases. There is on adjuster bar which allows you to take any slack out of the belt.

Steering Column

This is what connect the steering wheel to the steering rack (via a steering linkage made up of a couple of universal joints). This is simply a tube with the column going through the middle of it, each end of the column is splined for the steering wheel to grip it at the top and the linkage to grip at the bottom, The column is held in place at either end but a bearing, a bunch of washers and clips. The only issue that can occur with this is the wearing out of the bearings, this can be highlighted by a squeaking type noise when turning the wheel. A quick short term fix can be packing it out with more grease but ultimately the bearing will eventually need replacing.

Steering Linkage

This connects the steering column to the steering rack. This is made up of 2 univeral joints and is joined together by a rubber coupler. The universal joints are required due to the steering column being at a different angle to the steering racks pinion gear.

Steering Wheel

Main article: Steering Wheels

Common Problems

Vague Steering

Obviously with age and regular use the the rack mechanism can wear and introduce play to the steering, this can be seen by there being a delay from turning the steering wheel to the front wheels steering. However a more common issue for this feeling is the rubber guibo in the steering linkage having broken up, meaning there is play in the linkage. You can either replace the rubber guibo with an OEM part or make a custom solid spacer.

Maintenance

The steering system is relatively simple on an E30, and as such the main requirements are to keep the rack in good condition and topped up with fluids. Changing the fluid regularly will keep the rack clean, but you must also pay attention to the tie rod ends.

Upgrades

Faster Rack

While the steering of an E30 is a charm of feedback-response, neither too heavy or too light, many of the more spirited drivers find the standard rack too long, in the sense that it takes too many turns from one full lock to the other. Fitting a faster rack from a BMW Z3, E36 (non M) or E46 is a common and simple upgrade, but for those looking for bigger increases, fitting a rack from an E36 M3 can bring dramatic improvements.

The Z3, E36 & E46 racks all bolt straight into position on the subframe with no modifications but the do need 8mm of spacers as they are thinner than a E30 rack, you can keep their original track rods as well if you desire but certainly with the Z3 and E36 versions they can cause clearance issues if you are running larger than standard brakes. However the rest of the install isn't quite so simple due to the different angles of the pinion gear and positioning on the pinion of the PAS feed and return pipes. You can either bend your existing pipes with some trial, error and hope in that you don't kink or split them or you can buy custom pipes (Message E30Zone user DanThe for these & custom steering linkages). The other issue can be fouling of the steering linkage on the exhaust downpipes/manifold again due to the angle of the pinion gear, this is dependant on the engine and manifold you are using, you can either make a custom steering linkage like the one in this guide or one can be purchased from DanThe which involves the use of E34 steering UJs, one of which has to be stripped down and mated to an E30 UJ.

This thread is goes through how to fit a Z3 rack to a 318iS.

The difference between an E30 (front) & E36 rack.