I just replaced the bushings on my '64 230sl steering coupling. Since I'm in the process of completing the restoration, the instruments were still out of the dash and I was able to remove the seat to get more working room. It was relatively easy to remove the steering column as well. That's the only way I would attempt the coupling bushing replacement in the future.
I started by leaving the column in place and moving the steering box. That was relatively straightforward. The problem came in trying to re-install the newly refurbished coupling. Rather than struggle with the heavy steering box and getting that aligned with the coupling, I took a different approach. I re-fastened the steering box to the frame. I then installed the coupling on the steering box and then tried to get the steering column aligned and then attached to the coupling again. Even with my head down under the dash, feet on the parcel shelf I couldn't see well enough to align the steering column with the coupling -- also it was difficult (I'm doing this by myself) to maneuver the column into the coupling.
Plan B - I removed the steering column -- pretty easy task - unbolt the fastening strap, unplug the multi-pin, and loosen the 10mm nut holding the ignition lock and twist it out of the column. The column is then easily removed. I removed the coupling from the steering box, attached it to the steering column while the column was on the bench. For re-installation, I created a loop from some small diameter line that I ran through the two holes to which the steering column strap is attached. This gave me a loop that I could run the column through and still have plenty of maneuvering room for moving the column up and back when attaching the column/coupling to the steering box. Since I had painted marks on both the steering box and steering column splines before I removed the coupling, getting them aligned on reinstallation was not that hard except for the part where you have to contort yourself into the footwell (I'm getting pretty good at it now) . In my experience, having the coupling on the column made installation much easier. Once the coupling was attached, I removed the line loop and re-installed the column strap. And with this method you don't even need to remove the steering box. All of the reinstallation went very quickly with this method.
While the column was on the bench, I cleaned it up. The cover plate didn't have a gasket - it was previously attached with just 2 of the 5 10mm bolts. I inquired of the Classic Center on what a new gasket would cost. It was $366 -- yes - $366. I decided to use some off-the-shelf foam weatherstripping instead ( 3/8inch wide and 1/4 inch thick compressible closed cell foam).
When I bolted up the coverplate after reinstalling the steering column and coupling, the steering would bind. It was the coupling (the ears) hitting the coverplate. I backed off the coverplate and that eliminated the binding. The makeshift gasket I formed using weatherstripping was not thick enough to create the proper distance between the coverplate and the firewall to which it is bolted. I'll have to either buy the expensive gasket and go through that whole steering column contortion again to install it or just live with a "backed off" coverplate for now.
So, if any of you have had similar problems let me know if the proper gasket eliminates them (In the SLS picture the gasket looks pretty thick).
Also, I'm wondering if I have the coupling installed properly. When it came off the car, the coupling had the bushings on the steering column side. All the pictures I've seen in manuals etc. show the bushings on the steering box side. That is the way I reinstalled it - bushings on the steering box side -- pins on the steering column side. I'm looking for confirmation that that is the correct orientation for the coupling.
By the way - the car drives like new - steering is very tight and precise.
