[KTL]

To the original poster, what year car are we talking about here? Reason I say that is because of the details other fellas shared. 1985 and older CV axles have a different type of sealing method, using a pesky gasket between the CV joint and the receiving axle flange- at both ends. The 1986-up axle uses a grease cap which does a real good job of sealing.

However, if the sealing is good, regardless of axle type, you still can get leakage that is not coming from the boot. Often times people will get grease in the bolt holes and that grease slings out.

The different axle types also have different means of clamping the boots. 1985-older have the CV end mechanically crimped to the boot flange and the shaft end secured with a strap. The 1986-newer have straps at both ends.

Got a friend who's a pro mechanic (Jeep/Dodge/Chrysler) and has been noticing this issue with his '87 Carrera. Can't seem to find the source of the grease even though he personally replaced the boots on axle and has periodically checked them to see if they are loose, split, whatever. Weird.....