I have a 2000 V6 Ranger, 4 x 4. When I switch into four-wheel-drive I hear the Xfer case engage. There’s a clunk, a normal clunk.I have replaced the PVH hubs with manual lockers.It sounds like everything is engaged properly, but no power is getting to the wheels.During the last heavy rains, I got into some mud and tried to see if the front axles were turning.I couldn’t really tell.Are there other engagements, little clutches or anything between the transfer case and the wheel?Is there a good block diagram of the four-wheel-drive system, both mechanical, vacuum and electrical?