4WD Questions
I plan to purchase a new tow vehicle within the next two years. At the present time, I am towing a 3500 lb travel trailer with a 2006 Honda Pilot 4WD. The 4WD is Honda's name; actually, it is AWD wit...
Forum Discussion
Terryallan wrote:
Thing is. there is a HUGE difference between real 4 wheel drive, and All wheel drive.
4 wheel drive is when all 4 wheels have power to them. And so when you turn a true 4x4. The difference in wheel speed from the inside to the outside. Binds the axle, unless one tire can slip. Needing a slippery surface to slip on. OR the trany is burned to a crisp.
All wheel drive. Is usually only 2 wheels engaged at a time. One on the front, and one on the back. Should one, or both of those wheels slip. they are instantly disengaged, and the other two are engaged. Should those slip as well. The system tries to engage the other two again. And if that don't work. The system "CAN" disengage all four. No damage done. But the vehicle won't move.
So If you are never going off road / pavement. All wheel drive is usually good enough. But in heavy snow, mud, or sand. Real 4x4 is a must.
The only difference between 4WD and AWD is the that the transfer case allows the front axle to turn faster or slower than the rear. Both have differentials on each axle to account for the difference in speed from outside to inside.
The reason 4WD binds on pavement is because the tire runout is slightly different between the front and rear or when you turn corners the front has to travel further. A differential or clutches in the transfer case of an AWD allows this to happen. A 4x4 must slip the tires to even things out.
Even 4WD with open axle differentials really only powers one front and one rear wheel. That can be changed with limited slip or lockers.
Some modern AWD & 4WD systems make use of individual wheel brakes to help direct the power to the tires with traction in effect acting like an electronic limited slip.
