[W126 Coupe] Front Sub-Frame Bushing Dilemma

[Elm Zobens]

Has anyone else run into issues when replacing the 4
large rubber front sub frame bushings?
I've been playing with the front suspension of my 86'
560 SEC since July (no, not everyday- I'm not that
slow ;-) and I just seem to run into one pain after
another.

I originally replaced the front sub frame bushings
with some off brand that I had picked up on ebay a few
years back. When I tried to tighten them (80 NM-
Correct?), they shattered like glass. I then got a set
of MB replacement bushings and this week, I've had 1
of the 4 shatter on me.
I even went and bought a new beam-type torque wrench
before attempting the last set, to make sure I wasn't
over tightening.
Has anyone else had these issues?
It seems like a poor design to have such a critical
suspension item be so fragile. The one side I was able
to get together, I torqued to only 70 NM for fear of
shattering those as well. I would think these items
should withstand a fair amount of over tightening
before cracking and not be so close to their limit
with the factory torque rating?!
My concern now is that if I do get them all together
and tighten them to only 70 NM, what's to say a little
aggressive driving won't fatigue these as well until
they crack?
Does anyone make replacement bushings where the cups
are out of STEEL instead of these weak aluminum
inserts??
Any advice would be GREATLY appreciated!
Thanks-
Elm Zobens
86' 560 SEC