4X4 Set up Question
Thread Starter
|
5th Wheeling
Joined: Jul 2003
Posts: 26
Likes: 0
4X4 Set up Question
I have a Mountaineer with AWD. With the hubs and diff always working it gets poor gas milage. I would like the larger Expedition and need to know how the 4x4 system works. I would look for a '99 or maybe '00 model. Are the hubs auto or constant lock? Is the transfer case manual or electronic? What kind of milage do you get with yours?
Part Time Farmer
Part Time Farmer
Logistics Pro
Joined: Oct 2000
Posts: 3,960
Likes: 5
From: All over Texas
The Expy's in question have the A4WD which stands for "Automatic 4 Wheel Drive." It is a fully electronic system that runs in 2WD all the time then automatically switches into 4WD if the sensors sense tire slip and spin. You also have shift on the fly 4WD ability via a dash mounted switch. Gas mileage is poor, but worth it. I get around 10.5 city and 15 highway with a 5.4L engine and 33" tires.
Freshman User
Joined: Jul 2003
Posts: 27
Likes: 0
From: Greensboro, NC
Buzzard, I had the impression that AWD on Expeds shifts from rear axle to front axle, depending upon which has most traction. To get both front and rear locked together, you must activate 4wd. ??? Make sense??
Posting Guru
Joined: Sep 2002
Posts: 2,297
Likes: 0
No, Buzzard has it right.
From the wise men of Ford Motor Company, as applied to 1999-2002 Expeditions:
In A4WD, the generic electronic module (GEM) varies the torque split between front and rear drivelines by controlling the transfer case clutch. The transfer case clutch allows for slight speed differences between the front and rear driveshafts which normally occurs when negotiating a corner on dry pavement. When the rear wheels are overpowered, the GEM detects this slip condition, and the duty cycle to the transfer case clutch is increased until the speed difference between the driveshafts is reduced.
From the wise men of Ford Motor Company, as applied to 1999-2002 Expeditions:
In A4WD, the generic electronic module (GEM) varies the torque split between front and rear drivelines by controlling the transfer case clutch. The transfer case clutch allows for slight speed differences between the front and rear driveshafts which normally occurs when negotiating a corner on dry pavement. When the rear wheels are overpowered, the GEM detects this slip condition, and the duty cycle to the transfer case clutch is increased until the speed difference between the driveshafts is reduced.
Thread
Thread Starter
Forum
Replies
Last Post
Farmer_Jack_13
1999 - 2003 7.3L Power Stroke Diesel
5
Jan 26, 2017 09:27 PM
Lazy Farmer
1973 - 1979 F-100 & Larger F-Series Trucks
3
Nov 30, 2016 09:05 AM
old broke prospector
1961 - 1966 F-100 & Larger F-Series Trucks
5
May 2, 2013 08:47 AM
