I am about to get a 2002 X. I noticed that the front wheels have locking hubs but the four wheel drive is advertised as four on the fly. Will I have to actually get out of the truck to engage the four wheel drive?
Thanks,
Mike D.
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2006 F350 Super Duty 6.0l PSD, white CC SRW LineX
LOOK CLOSER AT THE HUBS. THEY SAY LOCK & AUTO. WHEN IN AUTO ALL YOU HAVE TO DO IS SWITCH TO 4X4 IN THE CAB AND THE HUBS AUTOMATICAALY LOCK IN. IF YOUR GOING TO GET INTO SOME HEAVY DUTY 4XING ("4WHEEL LOW RANGE") YOU SHOULD SWICTH TO LOCK MANUALLY.
Hello Mike,
No, you will not have to get out an lock the hubs, unless you either do not want to use the ESOF (Electronic Shift On the Fly) system or 1 or both front hubs fail, while in the "Auto" position.
The hubs have 2 setting- "Auto" & "Lock". When the hubs are turned to the "Auto" position, the system functions as a "shift-on-the-fly" type system, which allows you engage 4WD at any speed below 55mph. In addition, when the hubs are set to the "Auto" position, the front axle and front driveshaft remain "unlocked" from the drivetrain until the driver turns the dash-mounted dial to either 4H or 4L. When the dial is turned to either position, a vacum system is activated, which in turn engages or "locks" the front axle and front driveshaft to the vehicle drivetrain, giving you 4WD mode/operation.
When the hubs are in the "Lock" position, the 4WD system functions in the same manner as a standard system that uses traditional "Lock"/"Free" hubs. If the hubs are in the "Lock" position and the dash-mounted dial is in the 2H position, the truck is in 2WD, but the front axle is engaged (however not under power, i.e.- "free spinning/wheeling"). If the dash-mounted dial is moved to either the 4H or 4L position, the transfer case engages, locks the front drivetrain to the vehicle drivetrain, giving 4WD mode/operation. NOTE: To the best of my knowledge, you cannot engage the 4WD system while the vehicle is moving when the hubs are set to the "Lock" position.
Basically, I beleive F*rd designed this system this way as a backup for their shift-on-fly system (known as "ESOF"). In the event 1 of the nubs will not engage while in the "Auto" position, the operater can set both hubs to the "Lock" position and still have 4WD.
When I purchased my 2001 F-350, I couldn't figure out why F*rd designed the 4WD system in this manner. Then I thought about and this is the best explaination I can come up with, but if anyone knows different, please tell.
Ryan
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2006 F-350 Crew Cab, shortbed, SRW, 6.0 PSD/auto, 4x4, Lariat, White/Tan, 3.73 L/S, ESOF, moonroof, RECON smoked 3rd brake light, cab lights & mirror signal lights and more to come. Pics
Fords automatic hubs have been notorious for failing. I think i went through 4 sets before I finally switched to manual hubs in my Bronco.
The design is for the situations where you get stuck and can't generate any movement by the vehicle for the hubs to engage automatically. You can step out and manually lock them, then the 4x4 will work. If you notice, it takes a little movement for 4x4 to automatically engage. There are times when the front wheels are just in the right position to not engage immediately after switching to 4x4 which can really be disappointing when you're stuck and truly need 4x4 to free the vehicle.
When they are in the "lock" position, the front front drivetrain comonents (axle shafts, ring and pinion, driveshaft, etc) are spinning even if you have it in 2HI. This will reduce your gas mileage because of the extra parts the vehicle has to "turn" while driving. You can, however, engage 4x4 on the fly even with the front hubs in the "lock" position. You will not be able to engage 4-LO while moving, though. Be smart and don't drive on dry pavement with the hubs in the "lock" position because binding will occur when you turn your wheels.
I'll bet 95% of Excursion owners never use the "lock" feature on the hubs. I haven't, yet.
Auto hubs are not always reliable in very cold weather. If you attempt to engage them before they warm up, they might chatter (slip) before they fully engage. Enough of this and they'll either blow out when they finaly lock at speed, or wear out internally from the chattering. You could use the manual lock the "night before" if you were expecting a temperature drop, and needed the 4WD to get out the next day. Its a nice back-up in the event that the vacuum pump or system develops a problem, and you need 4WD.
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7.3 Excursion, it's a diesel thing.
Chicago MOB member.
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