Yeah I saw it a while ago when it first came out. Im sure my truck could make it up in 2WD. My stock limited slip still works for now.

 

The problem is that a clutch-based limited slip requires SOME amount of traction to start and continue working. For rock crawling and other such activities that may leave a tire completely off the ground with no traction at all, LSD won't really work. If the rollers on the ramp were well lubed and in good condition, there may not have been enough there to allow the LSD to actuate and keep working, assuming there was an LSD in that truck at all. Of course, if they'd dropped a locker into the front diff, it wouldn't have mattered

 

Like I said I'm confident my truck would make it up in 2WD, whether you disagree or not is fine with me firekite.

 

The other video I saw was different but the same principles.

 

I said there may not have been enough there to allow the LSD to actuate and keep working.

Regardless, if the truck in the video had a locking rear diff and the lock were engaged, there would've been no problem at all. That clearly was not the case.

 

So regarding the ELD, which I have on my '11 f-250, 4x4. Is the anyway to keep it from automatically unlocking at 25mph? I've got the ESOF and you have to pull the switch out to lock up the rear diff, but somewhere in the ECU or where ever, it unlocks at 25 regardless of what you're doing. I was just curious if there was a "gray wire" type modification that could be done.

 

I doubt it and it wouldn't be safe anyway. I you tried to pass someone at 30 mph+ and floored it on ice or gravel you could easily spin out. I wouldn't touch it.

 

The only reason I asked was because it senses 25, it unlocks. Regardless of me not actually doing 25. For instance both tires spinning. There is no way I'd leave it locked up on a street or with other people/vehicles around. I just have one "hill" that I always go over, and even when locked the tires slide, the pickup in the trans sees 25, and everything unlocks. Kinda annoying.

 

But safer. Actually when you are going up that hill both tires are pulling equally until one breaks loose and then the other one is keeping the truck tracked even though it isn't pulling much. I wouldn't mess with it myself.

 

Yeah, if you're spinning both tires loose where it looks like you're running over 25mph while locked, you may not be doing it right regardless. And the LSD will still apply regardless.

 

https://www.ford-trucks.com/forums/8...ar-locker.html
The above thread may help you in your persuit to extreme happiness and traction.

 

good question about the locker turning itself off at 25mph....I just noticed it myself the other day when playing with it.

My question is.....in 4wd mode does it lock the front and rear automatically or do you still have to pull the switch out? If so is it only lock in 4wdH or Low?

Also I think I rear somewhere the front hubs lock electronically and you can also lock them manually. Is this true?

 

There's a difference between locking in your hubs and a differential locker. You have to pull the 4WD selector **** while parked (or barely moving) to engage the locker. Give it a second or roll forward slowly, and it'll let you know it's engaged. I'm pretty sure it will engage regardless of which 2HI/4HI/4LO position you're in at the time. They put the 25mph safety release on there because realistically you should never really find yourself in a position where the locker is actually required (or helpful) out on the road, and they're concerned people will forget they left the locker on and potentially trash the differential, the tires, or get themselves into an unsafe situation of some sort. It's just a nanny thing.

A differential locker will actually cancel out the differential's ability to allow the axle shafts (and thus the tires) to turn at different rates. Just like the outside of a record is covering a little more distance to make a full revolution on the turntable and is thus turning faster than the inner edge of the record, when you turn at an intersection (or any time you're not going exactly straight) the outside tire has to cover more ground than the inside tire, so it's turning faster. The function of a differential, as indicated by its name, is not just to take torque from the driveshaft and transfer it to the axle shafts but to allow those axle shafts to turn at different rates to accommodate that kind of normal driving. One of the side effects of that function is that it means the torque gets sent to whichever tire is spinning faster, which is why you'll see someone on the side of the road with one tire on pavement and the other in mud, and it's only the tire in the mud that's spinning wildly, because it has no traction.

A "locker" locks the two shafts together so that they're not allowed to turn at different rates, negating the differential action and evenly distributing torque between the two axle shafts no matter what. That kind of sucks on high-traction surfaces like pavement because when you turn at the intersection the outside tire can't turn faster to cover more ground like it needs to, so it will skip and hop and protest loudly. But off road it's great. In the situation where you've got one tire on pavement and one in mud, only 50% of the torque is being sent to the tire in the mud instead of all of it, meaning the tire on pavement is getting 50% torque as well, and it has the traction to start moving you forward and out of the rut so that you don't get stuck.

In these trucks, a locking front differential is NOT available from the factory, only the rear. A dealer, off road shop, etc, can put in a locker after the fact (there are a number of options there), but from the factory the electronic locking differential is only available for the rear, with the upside that it's useful even in 2WD.

The hubs, on the other hand, are part of the normal front axle in 4WD. When in the "locked" position they engage the front axle shaft on that side so that when the shaft turns (i.e. when receiving torque from the transfer case because you're in 4WD) the tire turns, or when the tire turns (in 2WD but left locked) the shaft turns. When unlocked, it disengages the axle shaft so that as far as the shaft and differential are concerned, it may as well be sitting still; nothing turns. That means less drag, less wear on components, etc. There are automatic and manual hubs. Both are options on a new Super Duty (manual is standard on entry trims, auto standard on higher end trims).

When driving normally on the road, the hubs should be unlocked (or in "auto" mode) so that nothing is engaged and nothing is turning while you're in 4WD. The difference is when you're off road or backed up on a slippery boat ramp and it's time to engage 4WD. With manual hubs you have to stop, put it in park, jump out and potentially slog through mud, rain, whatever, to turn the driver's side hub by hand from unlocked to the locked position, then slog around to the passenger side and do the same, then slog back around to the driver's side and climb back in, engage 4WD, and go. With automatic locking hubs, you engage 4WD and go, and they'll lock automatically. You generally leave them in the "auto" position (unless you just feel like manually turning them to the locked position). As with all things they can eventually wear out or have problems, but the manual option is still there in those cases.

Hope that helps.

 

yes thank you for that helpful explanation.......so on my truck would it have an option on the 4wd switch that says its auto locking front hubs?

 

Heh, no, hubs are controlled at the hub. You turn them by hand from unlocked/auto to locked and back again. The difference is that if you have automatic locking hubs, you leave them in auto. When you put the truck in 4WD the hubs will therefore lock automatically, so you don't have to worry about getting out and manually turning them over to locked by hand.

Your 4WD **** will have 4 positions: 3 rotary and 1 pull. The rotary options will be 2WD, 4WD High gear (normal), and 4WD Low gear (for deep grunt and slow maneuvering offroad). Pulling the **** out will engage the rear e-locker. Pushing it back down into the normal position will disengage it for normal driving. There is no front locker unless you've had an aftermarket modification done.