Originally Posted by
T-Mar
Offhand, can't recall seeing a Shimano directive on this matter, as it pertains to square taper spindles. In the case their splined spindles, they are somewhat ambiguous, the wording implying that it's not necessary but is good practice.
On the other hand, Campagnolo documents from the same era specify thorough degreasing and even stipulate that the bolts must not be lubricated.
And to add another manufacturer, Phil Wood's instructions for installing cranks on their bottom bracket spindles include:
"To install your crank set, consult your original crank set’s installation instructions. A thin layer of grease should be applied to the spindle’s tapered surface before the crank arms are bolted on."