I stopped at a 4way stop last night and suddenly my Discovery wouldn’t go. I can not get the gearbox to engage to go forwards or backwards. Fluid levels are good both in the transmission and in the cdl. I have never been able to engage the low range on this one. And recently my cdl stopped engaging. Now if I rev it up and then put it into park I hear a clicking. I check the linkage and it seems to be working. Any thoughts?