FX4 Locking Differential
Senior User
Joined: Dec 2003
Posts: 212
Likes: 0
From: Spruce Pine, NC
That is correct Broncobran68. They do not have the stability/traction control. You will not find a traditional limited slip WITH the E-locker. It may be listed on the window sticker as standard equipment, but is replaced with the E-locker as the optional Axle Upgrade included with the trailer sway/advance trac. If you have leather seats it still lists the standard cloth on the window sticker. Same with wheels and paint.
However the E-locker is a requirement for the stability managment and not just a luxury upgrade.
However the E-locker is a requirement for the stability managment and not just a luxury upgrade.
Senior User
Joined: Sep 2004
Posts: 447
Likes: 0
From: Colorado
I stand corrected from my last post where I stated on my window sticker it says LS and E-Locker. My window sticker in fact only says e-locker and all the stablilty/traction control stuff. I think whalebird is right...at least he is according to my sticker.
Cargo Master
Joined: Sep 2005
Posts: 2,945
Likes: 866
From: Montana
Sorry but I am not trying to argue, but it cannot be both. It is an open diff when unlocked, regardless of the rooster-tail test. The tracion control system demands an open dif. That is the only reason Ford has the e-locker, otherwisw they would be using the clutch type diff they have always used.
How can it not be both? There are diffs available that acts as a L/S when unlocked then can be locked. Not saying that the e-locker used by ford IS one of these, but it COULD be.
Senior User
Joined: Dec 2003
Posts: 212
Likes: 0
From: Spruce Pine, NC
Can't be arno. have someone hold the other wheel. It is an open diff. if you have traction control. new diffs are tight to begin with. They have enough internal friction to simulate a LS. Furthermore-variable slip diffs are usually hydrolic, not electronic. and will only work when running.
Laughing Gas
Joined: Nov 2005
Posts: 983
Likes: 3
From: Detroit 'burbs
Ok Im more confused then ever. When (if?) I buy a FX4, Im going to have traction control AND the E-locker? I know What the E-locker does and how it works. I know how the limited slip works. I have a 07 XLT 4X4 now with limited slip. HOWEVER, if I get the new FX4, would the traction control be sufficient for driving in snowy road conditions or would I use 4HIGH like I do with my 07? Now repeting what I posted earlier, my buddy told me using 4HIGH with the E-locker on snowy or icey pavement like I do now with my 07's Limited slip 4X4 will damage the transfer case because a locking differental is intended to be used only in extream off road conditions. What is the truth here?!? lol
Freshman User
Joined: Apr 2007
Posts: 37
Likes: 0
Ok Im more confused then ever. When (if?) I buy a FX4, Im going to have traction control AND the E-locker? I know What the E-locker does and how it works. I know how the limited slip works. I have a 07 XLT 4X4 now with limited slip. HOWEVER, if I get the new FX4, would the traction control be sufficient for driving in snowy road conditions or would I use 4HIGH like I do with my 07? Now repeting what I posted earlier, my buddy told me using 4HIGH with the E-locker on snowy or icey pavement like I do now with my 07's Limited slip 4X4 will damage the transfer case because a locking differental is intended to be used only in extream off road conditions. What is the truth here?!? lol
The locker is not on when you are in 4 wheel drive unless you pull the 4x4 **** out on the dash. I have not used the e-locker on my truck yet. I don't drive on anything but the street and snow/ice.
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
10 Best Ford Truck Engines We Miss the Most!
Joe Kucinski
2026 Shelby F-150 Off-Road: Better Than a Raptor R?
Brett Foote
2027 Super Duty Carhartt Package First Look: 12 Things You NEED to Know!
Michael S. Palmer
10 Most Surprising 2026 Ford Truck Features!
Joe Kucinski
Top 10 Ford Trucks Coming to Mecum Indy 2026
Brett Foote
5 Best / 5 Worst Ford Truck Wheels of All Time
Joe Kucinski
Ford Super Duty: 5 Things Owners LOVE, 5 Things They LOATHE!
Joe Kucinski
Every 2026 Ford Truck Engine RANKED from WORST to FIRST!
Michael S. Palmer
The Best F-150 Deal of Every Trim Level (XL through Raptor)
Joe Kucinski
Laughing Gas
Joined: Nov 2005
Posts: 983
Likes: 3
From: Detroit 'burbs
Yes, you will have traction control and e-locker. As you can see everyone has differing opinions on the effectiveness (or lack thereof) of the traction control when driving in snow. I had an '04 Lariat 4x4 with the 3.73 limited slip and it got around good in the snow in 2wd. My '09 FX4 (in 2wd) gets around just as good if not better than my '04 and I do not disengage the traction control.
The locker is not on when you are in 4 wheel drive unless you pull the 4x4 **** out on the dash. I have not used the e-locker on my truck yet. I don't drive on anything but the street and snow/ice.
The locker is not on when you are in 4 wheel drive unless you pull the 4x4 **** out on the dash. I have not used the e-locker on my truck yet. I don't drive on anything but the street and snow/ice.
ooohhh so this is something I wasnt aware of...So just putting the FX4 in 4WD does not engage the locker, you have to also pull the **** out as well? I thought it was like the rest of ESOTF transfer cases where you just turned the **** but with the FX4 it was E-locker or nothing. So you can use 4WD without the locker as well?
Freshman User
Joined: Apr 2007
Posts: 37
Likes: 0
ooohhh so this is something I wasnt aware of...So just putting the FX4 in 4WD does not engage the locker, you have to also pull the **** out as well? I thought it was like the rest of ESOTF transfer cases where you just turned the **** but with the FX4 it was E-locker or nothing. So you can use 4WD without the locker as well?
Senior User
Joined: Dec 2003
Posts: 212
Likes: 0
From: Spruce Pine, NC
exactly soundwave. There is a light in the lower left of the 4x4 swith that lights up after blinking a couple of times when engaged. You will notice that you cannot pull the switch out in 4x2H. The diff has to be open for the stability managment to function. That is why the owners manual goes into such detail and warns against improper 4x4 usage - You lose the swiftest, most effective safety system on the vehicle.
Cargo Master
Joined: Sep 2005
Posts: 2,945
Likes: 866
From: Montana
Driving on snow/ice with a locker will not hurt the locker... you just don't want to use it on flat, dry surfaces... It still won't hurt the locker on those surfaces unless you turn. When you turn, the outer tires travel a further distance. If the locker is engaged, then the inside tire will want to spin and catch up to the distance the outer tire traveled. If you are on flat, dry surface when this happens, it could snap an axle or the locker, etc. If you are on a slippery surface, ie; mud, snow or ice, the inside wheel can slip freely to catch up to the outer wheel, not causing any damage.
What some of the guys are saying is that you may not WANT to drive with the locker engaged because that inside tire spnning can cause you to lose control easier, such as on ice. I don't know what kind of problems, if any, will occur with traction control. On vehicles without traction control and a locker engaged, the inside tire trying to catch up spins, and causes the back of the vehicle to lose traction on ice. Hope that is understandable.
What some of the guys are saying is that you may not WANT to drive with the locker engaged because that inside tire spnning can cause you to lose control easier, such as on ice. I don't know what kind of problems, if any, will occur with traction control. On vehicles without traction control and a locker engaged, the inside tire trying to catch up spins, and causes the back of the vehicle to lose traction on ice. Hope that is understandable.
Post Fiend
Joined: Nov 2001
Posts: 7,698
Likes: 4
From: Neenah, Wisconsin
QUOTE DIRECTLY FROM FORD
"The 2010 F-150 comes equipped with standard AdvanceTrac® with Roll Stability Control™* (RSC®). This advanced technology uses a combination of reduced engine power and selective wheel braking to help the driver maintain control. Corner too quickly or swerve to avoid an object and RSC® will automatically use its industry-exclusive gyroscopic sensor to measure vehicle roll, then apply the proper response to help keep your truck under control."
You can order a truck with rsc and either the elocker or the LS....
They are not exclusive features....
"The 2010 F-150 comes equipped with standard AdvanceTrac® with Roll Stability Control™* (RSC®). This advanced technology uses a combination of reduced engine power and selective wheel braking to help the driver maintain control. Corner too quickly or swerve to avoid an object and RSC® will automatically use its industry-exclusive gyroscopic sensor to measure vehicle roll, then apply the proper response to help keep your truck under control."
You can order a truck with rsc and either the elocker or the LS....
They are not exclusive features....
Cargo Master
Joined: Sep 2005
Posts: 2,945
Likes: 866
From: Montana
Just checked out the GKN website... They say the locker can be used with any limited slip differential...Again, doesn't say it IS combined with LS, but then again, doesn't say it IS NOT.
While everyone has thier user manuals out... Can anyone tell me if the differential for the locker required friction modifier? The site also mentioned NO aditives or friction modifiers are needed for the locker... So if the FX4 differential DOES require the friction modifier, the transitive property would have you believe that it indeed DOES have LS along with the locker... And yes, the traction control works on trucks with a limited slip...
While everyone has thier user manuals out... Can anyone tell me if the differential for the locker required friction modifier? The site also mentioned NO aditives or friction modifiers are needed for the locker... So if the FX4 differential DOES require the friction modifier, the transitive property would have you believe that it indeed DOES have LS along with the locker... And yes, the traction control works on trucks with a limited slip...