Diff fluid in '92 325i?

["Douglas M. Max" <dmax@xxxxxxxxxxxxxxxx>]

Since I'm at 80,000 and trying to keep my '92 325i pristine I want to
change the fluids I can.

My dealer says my rear differential is sealed and that the fluid can't
be changed.  Noting the previous poster who changed his in a more recent
model, I'm wondering about the voracity of this.  Can and should the
differential fluid be changed in a '92?  Is it critical, nice to do, not
a bad idea?

Also, what about other fluids?  I know the cooling and brake fluids.
What about transmission, steering, anything else?  Must, can, okay not
to?

Cordially,

Doug in NJ

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