BMW E30 Close Ratio Steering Rack Swap

There are 3 different ratios that E36 cars came equipped with.  All non-M 3-series coupes and sedans 92-98 came with a 3.2 turn lock-to-lock rack. M3s and M Z3s 96+ had a 3.2 ratio rack as well.  95 M3 had a 3.0 turns lock-lock rack and a 2.8L Z3 96+ had a 2.7.  All of the racks look virtually the same, Z3 rack looks different but all the mounting points and the hose attachments are the same as all other E36 racks.  It is really easy to tell the racks apart by just looking at them.  Silver (unfinished aluminum) racks are 3.2, Gray (anodized) are 3.0 and Z3 racks look like E30 racks with a steel plated tube.

Installing a close ratio rack in E30 without an airbag:

To install a close ratio rack in your E30 not equipped with an airbag you will need to shorten you steering knuckle.  To shorten it grind down the rivets that hold the two halves of the steering knuckle together.  Here are the parts you will need to shorten the knuckle:

BMW Part #
Quantity
Description
72-11-8-119-268
1
Spacer
72-11-1-977-925
2
Nut
7/16 Fine thread bolt
2
About 2” in length

E30 Steering Knuckle

Cut the 72-11-8-119-268 spacer in half, this spacer goes in between the two halves of the steering knuckle (see pic).  Drill the center hole of the spacer out for the 7/16 bolt to fit through.

BMW E30 Steering Knuckle

You will need four BMW Part # 72-11-1-847-480 spacers to mount the steering rack to the front sub frame.  Use one spacer on the bottom and one on the top of the steering rack mount.  The steering knuckle has to be bolted together with the rack installed in the car.  Put some lock tight on the nuts to keep them from coming loose.  You will also need a high pressure line out of an E36, in some cases its possible to use a stock E30 high pressure line but you will have to bend it to make it fit.

Installing a close ratio rack in a car with an airbag:

Guess what? Its possible!  For the longest time I have been hearing from different sources that it is impossible to install an E36 rack in E30 with an airbag when in fact it is actually pretty simple.  There is no need to modify the steering knuckle, stock knuckle works just fine.  The thing that does need to be modified is your firewall.  For the E36 rack to fit you will need to move the opening in the firewall down and to the right about 1.5-inches.  The part that is outlined with a marker needs to be ground away with a dremel.

BMW E30 Rack Swap Firewall

A black metal plate that holds the firewall seal in place, this plate is bolted on to the firewall from the inside of the car, will need to be replaced.  You will need to fabricate a new plate that will move the seal down and to the right.  See the picture, the new plate is on the left.

BMW E30 Rack Swap Firewall Plate

Install the plate and seal all the exposed metal with some 3M-body sealant to keep it from rusting.  The last picture shows everything assembled and of course don’t forget to use four spacers BMW Part # 72-11-1-847-480 for mounting the steering rack to the sub frame.  High-pressure line has to be out of an E36 or bend your E30 line to fit.

 BMW E30 Steering Swap  BMW E30 to E36 Steering Swap