In general an axle is a centre shaft for a rotating wheel or gear. So In general axle shaft is on which the hub of the wheel is mounted. In a rear wheel drive, on side on the axle is attached to the differential assembly and the other side is attached to the hub.
The average cost of a vinyl replacement window is between $400-$575 per window for a double hung. That price includes the cost of the new vinyl replacement window and the installation of it. The big difference in price would be for reasons like the manufacturer of the vinyl window (which series you go with in their line), grids, low-e and argon gas for example. Vinyl casement pocket replacement window:
A very quick and general answer to this question is that replacement windows can cost on average anywhere between $350-$995 (and up) per window opening for new energy efficient replacement windows. This is what we have found here in the Houston Texas metro area market.