grease rack when replacing boot? '88 5kcstq

[auditude at neta.com]

I'm replacing the boot on the rack I'm putting into my '88 5kcstq.
The Bentley says to lubricate the center bushing/o-ring, using
"gear grease".  This reads different to me than "bearing grease",
which is all I see in the local stores.  The only thing they have that
is labeled for gears, is "gear oil".

Should I look for a specific type of grease, or is it okay to use the
"disc brake, wheel bearing grease" I have already?  I don't want to
use something incompatible with what's already there, and I don't
want it to eat the boot either.  I heard that WD-40, for example, will
eat the boot.

The old boot on the rack I'm replacing looks pretty bad in the
middle, all chewed up and kinda disintegrated.  It is much worse
than an on-the-car inspection would have indicated.  Both racks are
ZF remanufactured units.

I'd like to lube it while it's out.  What kind of grease should I use?

Thanks,

Ken