Is the steerng knuckle on a 1981 300SD interchangeable with later W126 cars?
 

I have a torn boot on the passenger side lower ball joint. I plan on replacing it in the next month or so, and would like to pull a steering knuckle out of junk yard, and take the knuckle to a shop and have them press in a new ball joint so that I can do the job at my convenience. My 300SD is my daily driver and only car, so this would make things easier for me. Thanks

Won’t that mean a new wheel bearing set?

Sixto
98 E320s sedan and wagon
02 C320 wagon

I can use the outer bearings from the 300SD spindle, and I'm pretty sure that the inner bearings are in the hub/rotor assembly.

'81 thru '85 are the same. In '86 the rotor diameter was increased, and the caliper relocated accordingly, which resulted in the need for a wheel diameter increase from 14" to 15".

That said, it appears that the caliper was changed rather than the knuckle, so a knuckle from '86-'91 should also match.

Thanks. A spring compressor isn't required for this job, correct? Order of disassembly will be caliper, rotor/hub, tie rod upper control arm nut, and lower ball joint with tool or hammer?