Main.TrailIndexPage | Steering System | Power Steering Power Steering
All models use the same power steering box. However, the steering columns (or spindles) are substantially different. The 230SL/early 250SL have split column (55&45) connected by a universal joint (50) as shown below.

The lower column is connected to the power steering box via the steering coupling (28). This coupling contains a plastic bushing (30) and a plastic washer (31) that fail over time and cause a fair amount of "play" or "wobbly" steering feel. Replacement of these parts is straight forward but can be difficult. To access the coupling remove the five bolts that fix the cover plate (117) to the firewall above the brake pedal, loosen the bracket (119) and slide the plate upwards along the steering column jacket (40). Unscrew both Allen bolts (35) on the coupling that keep the splined column and the splined input shaft on the steering box connected to the coupling. The steering box is attached to the chassis by three bolts that are accessible from the wheel well. To remove the steering box several methods have been described - here is the one posted by rogerh113:

I just replaced the nylon bushings on mine - not too complicated, but do review the postings here on doing it and pay particular attention to the alignment markings.... Not a difficult job, but do watch the alignment. Also did not need to jack up the car - no need to be underneath. A trick I found out the hard way - even if you mark alignment with the wheels straight ahead, rotate the steering wheel one full turn one way or the other prior to pulling down the coupling. If you don't, you will find that the steering arm at the bottom of the steering box will contact the lower 'wishbone' just before the coupling comes loose - really annoying...... By rotating the wheel, the steering arm will be on one side or other of the wishbone, and will clear nicely and the alignment marks will still be accurate.
Enochbell adds: Roger, your technique of turning the wheel 1 x made it a breeze, no need to touch any of the steering arm/tie rod assembly. Also, I did not need separate the flanges from the steering tube (the upper shaft) or worm (the shaft exiting the steering box). Instead I just removed the three bolts from inside the wheel well to free the steering box; removed the cotter pins (I HATE cotter pins)from the flange pins and then separated the upper flange from the lower flange. Reinstalled the fresh bushings in the lower flange and then squeezed the whole assembly back together. Probably not the book method, but it worked without worrying about aligning the tube and worm splines.

Note the groove in the input shaft on steering box shown in the photo. During reassembly the Allen bolts must pass through this groove!
The steering column on the late 250SL and 280SL cars is collapsible and therefor quite different.
280SL Steering Column:

Here the steering column (spindle) is connected to the input shaft on the power steering box via a universal joint (29). This universal joint is different from the one that connects the two shafts in the 230SL steering column as shown above and the two are not interchangeable!

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