Comprehensive Guide to LHD E30 Rack Swap: Installation and Steering Shaft Solutions
So you have finally decided to perform one of the most rewarding upgrades for your E30 chassis, the Z3/E36/E46 steering rack swap. The factory rack is 4 turns lock to lock, making it a chore to row through when you're carving up the canyon. The popular Z3 (non-M) steering rack (PN: 32131094038 or 32131095577) has the shortest lock-to-lock at 2.7 turns. The purple tag E46 Clubsport rack (PN: 32132229397) is another popular option due to its quick turning ratio and plentiful availability. In this article, we are going to assume you have already done your research and acquired a steering rack sourced from a later Z3, E36, or E46 chassis and focus on installation and making the connection from the E30 factory steering column to your upgraded rack with the components offered by Garagistic.
Preparing the New Steering Rack
With the OEM E30 rack removed you can get a side by side comparison and you will immediately notice they are very similar except for a couple of minor details. The mounting provisions on the E30 steering rack to mate it to the front subframe are physically taller than the later chassis steering racks by about 14mm. To solve this issue we offer 2 hardware kits for early model non-airbag chassis and later model airbag chassis, both of which include precision milled 14mm spacers to properly secure your new rack to the E30 front subframe. The spacer is meant to be placed on the top of the steering rack mount although it can be used on the bottom for a minor bump-steer correction on lowered cars. The non-airbag kit will also include the necessary spacers and hardware to shorten the E30 OEM lower steering shaft found here. If your BMW E30 has an airbag, all you will need is the spacers to mount the steering rack found here.
Note: You will have to modify the plastic steering joint alignment provision on the E46 steering rack as pictured below. We recommend using a cut-off wheel to remove the section outlined in red.
Steering Shaft Modification and Disassembly
Now that we have the necessary steering rack conversion kit for our application we can take a look at how we are going to configure our steering shaft to connect our new steering rack to the E30 steering column. The two variations are pictured below.
TAKE NOTE OF THE FACTORY ORIENTATION OF THE STEERING SHAFT COMPONENTS FOR REASSEMBLY
Early Model Non-Airbag Late Model Airbag
To modify the early model non-airbag steering shaft it needs to be disassembled by removing the flared ends of the 2 rivets securing the two halves of the lower universal joint together as highlighted below. This can be done with a drill or cut-off tool and the steering shaft should come apart with some gentle persuasion.
With the two halves separated we can install the shouldered spacers with the included hardware. Hardware should be tightened down snug plus a half turn with the spacers completely seated. It is unlikely this will ever need to be disassembled so we always recommend using a high-strength thread locker compound on the hardware as an extra safety measure. Due to tight tolerances, some steering shafts will require minor drilling with a 9/16 bit to fit our shouldered spacer.
Steering Shaft: Steering Flex Couplers
The last component that needs attention is the OEM rubber flex disk. Garagistic offers two replacement options for upgraded street and the all-out track builds. These are a direct replacement for OEM part number 32311153993 on 1984-1991 E30 325, M3, and 318. You can purchase them and find more info here on both the Delrin option and the Aluminum option.
Installation is similar to the non-airbag modification process. The flared ends of the 4 rivets securing the upper and lower universal joints to the flex coupler need to be removed to separate the steering shaft.
Reassemble in reverse order using the hardware provided in the Garagistic Solid Steering Flex Coupler Kit. Hardware should be tightened down snug plus a half-turn, and again, it is unlikely this will ever need to be disassembled so we always recommend using a high-strength thread locker compound on the hardware as an extra safety measure. This completes the steering shaft modification and you are now ready for the final installation of your upgraded steering rack. Installation tips can be found here.