My 87' 300E steering gearbox has blown the top gasket on the steering strut.
It appears that 10/87 was a change period for the design that differs from the Mercedes manual (46-0236) and David Petrk DIY article. 23 ball bearings later, the disassembled steering shaft assembly appears to come apart by turning the internal prong round nut requiring a special tool (per step 11). It must be very special as gentle coxing with a drive and WD40 produced no movement. I tried the external hex nut going around the round nut and no movement there. The steering shaft spins freely on the bearings in the housing so a new top seal just might put get power steering working again.
The gearbox is stamped with 124 461 0005. Has anyone else worked with this part of gearbox?
It sure seems like it should disassemble by getting one of these nuts to spin. The top of the steering shaft assy doesn't appear to have retaining clips allowing disassembly from the top either. Experienced help, suggestions or the "hey did you try this" feedback just might help me get travel back to normal. Thamks for consideration and expertise.

I have pictures to share but could not get them to attach to this post.

for those who read thru this post, the issue has been resolved.
Getting the hex nut to move was the key.
An overnight WD40 soak, a two foot pipe wrench (that's all I had big enough) and the appropriate amount of body weight were the secrets to disassembly. Not for the faint of heart but this part of the rebuild is done. Now if I can get everything back together before the rain/snow gets here.

The MB CD manual was pretty close but there were a few undocumented changes in the basic instructions requiring a bit of ingenuity and assumptions to get by.

yep it seems to work fine.
a big hint for anyone trying this DIY job.
check out the performance of trhe gearbox on the ground before puting it back on the vehicle.
oh yeah double check that all of the external snap rings are well seated.