I do not, by any means, recommend tightening the allen bolt that Larry was referring to. Basically, it gives the driver a sense that the steering play has been cured but in reality, the box just wears quicker and it can easily become dangerous to drive the vehicle. If you've got play, replace the coupling, and/or replace the box if it's leaking. I am sorry to oppose your suggestion, Larry, and I know that the information is given in your best interest, but when I was told that Mercedes strictly recommends against making those type of adjustments, and have witnessed the results of that, I can only recommend to replace the worn parts.
Precision Motorcars, Cincinnati, Ohio
'67 250SE Cabriolet
'79 6.9 (SOLD)
'93 300E 2.8