RS4 Steering Rack Upgrade DIY

[Denio24]

So this is actually a thing not many people may know about. Speculation was on the net that the RS4 supposedly had a tighter steering ratio, and I found out myself that it actually does. I hopped on the parts catalog online and found the rs4 part number and i found myself a unit from a local junker for about $50. I see units on ebay going for $150. 8E1422054C. I did compare the racks side by side and they are quite different internally. I made a quick video providing explanation. The stock A4 rack has a straight cut tooth rack, the RS4 has an angled gear design and im sure the pinion is different as well. If you compare the lock to lock turns inside of the car one may think that the ratios are the same but with the rack removed from the vehicle it is much easier to compare as there is no added factor of steering wheel slop, loose joints, etc. The ratio comes out to just under 14.9 which confirms the info on the net that the ratio is around 14.5. While I did find that there was an even tighter steering ratio around 13.1 perhaps that was from a b5 because the part number I have was from an RS4. Pictures and more to come.

Before removing the steering column bolt and the rack itself you want to disconnect the power steering return line that goes after the rack and empty the lines by moving the steering wheel lock to lock. This will help considerably. You can also empty the system by running the car with the line disconnected for a max of two seconds.

First things first, you want to center your steering wheel to straighten your wheels to make everything easier. Next step is to remove the 8mm hex bolt at the steering column.

Jack the car up from the front slightly and remove the driver side wheel, and slightly lift the passenger side wheel. Disconnect the tie rods from the knuckle on each side. You dont have to remove the passenger side wheel as long as you have access to the bolts. Loosen the steering rack bolts and remove the two bolts closest on the driver side. Keep the bolt on the passenger side 1 turn loose so you can swing the other side of the rack towards the car. Using some long extensions slide the extensions and 19 and 22 mm sockets up near where the driver side axle is and hit those bolts. This is much easier than tackling these bolts with box end or combination wrenches. Have a piece of paper towel prepared for a tiny bit of fluid to come out from the banjo bolts.

In preparation to remove the rack, undo the top strut mount bolts and swing the strut top hat outwards and to the front to give you clearance to remove the rack. Jack the knuckle from the lower control arm so it doesnt go anywhere. Remove the plastic dust cover, remove the steering column bolts and the last rack mounting bolt. Now you can easily remove your steering rack.

Great now you have your new rack, clean it up, clean the shaft with some scotchbrite to remove rust and wipe off with break cleaner.



Grease the rack end lightly with a moly grease..i just installed a fresh tube of molykote g4700



Time to button it up with new orings and the old boots since they weren't ripped.

You wil have to make a centering bolt that is M10x1.5 that looks like this



And it fits in here. This is only for installation and MUST be removed and replaced with the original bolt before you drive otherwise your wheels will not turn and you may damage your rack...doh.



Center the rack and you will find the hole



Install the rack again only mounting it on the bolt closest to the passenger side so you can swing it. Using new crush washers



Install the banjo lines. Using the set of extensions and reaching from bottom of the car up and through where the axle is, torque the bolts to spec (will be updated with specs).

Place the strut assembly back in place, install and torque the remaining steering rack bolts with blue loctite, and install the tie rods to the steering knuckle and torque to spec. Dont forget to remove the centering bolt after youve attached the steering wheel pinion with the 8mm allen bolt (torque to 22 Nm). Dont forget to add fluid, connect the lines, and bleed the rack.

https://youtu.be/KAYuyCN_4sc





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