WD40 may be a solvent, but, it frees up old oil
residues and usually makes the fans come alive
again.  I just have to use it once every couple
of months on the bearings.  Good synthetic lube
is probably better, after an initial WD40 clean
out, but, since I tend to be a tightwad, the WD
stuff usually suffices fine, on my machines.

Bob