Hi i have a fourtrak 2.8 tdx. i was checking the 4 wheel drive works ok and had all the wheels off the ground, put it in 4x4 and only the driver back wheel and passenger front wheel went round, the other two went round but no where near as fast. however when i reved the engine all four seemed to go at the same speed?!. i know it's not the hubs becuase i put new manual hubs on myself last week. i just want to know if this is normal or if something is going wrong.