skl1

2012 SuperCrew; 5.0L, 2WD, 3.31 Open Diff. Thinking of replacing open diff with electric locker, TrueTrac, or Limited Slip. Get stuck every couple years on mud field parking lot or hunting trail. Is Electric locker worth drilling hole in the case and running the wires over TrueTrac or Limited Slip? In bad mud, will TrueTrac spin? How about "regular" limited slip?

jdunk54nl

I wouldn't put in the E-locker, I would do one of the mechanical if I was starting from scratch.

jp360cj

A truetrac will have a higher torque bias tab most clutch limited slips, so it can't transfer more power to the tire with the most traction. They do very well as long as you can keep both tires on the ground and some weight on each. But nothing with match a locker for traction. The disadvantage of a selectable locker is you have to activate it. So if you don't activate it soon enough then it won't do you any good.

skl1

Well, my thought is that each time I've gotten stuck I had one tire with good traction. If I could have flipped the switch and locked the differential I could have pushed out past the mud trench the other wheel was in.

I wonder if the TrueTrac would have pushed me out, or if the wheel would have had too little traction to engage the other side of the differential?

Steve83

That's like asking the best color of paint for your contacts, or the best refrigerator to bake a turkey in. If you need to drive in mud (or any low-traction terrain), you need 4WD. And the TYPE of rear diff isn't very important. I do the hardest trails with 2 open diffs.

But with 4WD (usually). Getting home is far more about the driver than about the vehicle.You should learn where not to park, &/or how to drive out in 2WD. Download & read the manuals linked in this caption:


(phone app link)

Keep a bag of kitty litter in the bed when you're going to that mud field; or some traction aids (tire chains, mats, etc.), or a cheap little winch/come-along, or a tow rope/strap/chain/cable so someone can give you a tug on those rare occasions when you need it.

PerryB

I have one with a Truetrac (Son's truck now) and 2 with ELD's. Personally I'd take the Truetrac any day. It's fully automatic, you don't have to get out of the power to engage it. As mentioned earlier, you need to remember to engage the ELD before getting into the slop. If you try to activate the E-lock while experiencing one-wheel spin, unhappy things are apt to happen. Like a sharp "Bang" followed by a loss of function. The only "catch" to the TT is if you are in near zero traction conditions. There may not be enough traction to generate the torque needed to get it working. In that case, powerbrake it a little and away it goes. I love the TT and want to put one in the '13 in place of the current ELD.

marshallr

Limited Slip is, "limited" in how much it helps. If a truck came with a locking diff it can help, but I wouldn't pay to upgrade a 7 year old truck with a locking diff. It just doesn't help that much. Even with 4X4's a locking diff's most useful during those times when one wheel is off the ground. I'd just save my money and apply what I'd have spent on upgrading toward trading for a 4X4 truck.


Pushing the parking brake in 2 or 3 clicks will send power to the other wheel with an open diff. Which is exactly what traction control does electronically. It applies brake pressure to the spinning wheel and diverts power to the other one.

PerryB

Yep, that trick actually works pretty well assuming the park brake is properly adjusted and in good working order. The only catch is you have to apply enough brake to exceed the breakout torque of the tire with the most traction so the diff sees the resistance as equal. I once used this method to get a friend un-stuck in his car. He parked on a muddy shoulder with the left wheel still on packed gravel. I applied a moderate amount of E-brake and started leaning into the throttle. It powered itself right back up onto the road. When he first watched me put on the brake I think he thought I had lost my marbles. I never did succeed in him grasping why it worked. It worked...
Traction control has the huge advantage of being able to apply the brakes independently of each other (and automatically) whereas the Okie posi puts both sides on equally so you have to get into the throttle somewhat harder to overcome the brakes, but it beats walking home with muddy shoes.

BareBonesXL

TrueTrac or Traction-Lok would be the simplest and cheapest. Keep your gears and housing and just change the diff and bearings. It will be better than open but not as good as 4WD. You need weight on the wheels or either of those will lose traction. See the threads about sand bags.

Many people don't really understand the basics behind the clutch limited slip or the helical diffs. Some get side-tracked mentally by the word "limited". Limited slip limits tire slippage. That's a good thing. There's a lot of bad information out there about how diffs work, even on what look like pro sites. The Traction-Lok will always apply power to the wheel with traction, even if the other wheel is off of the ground. It's described in the Service Manuals. The common helical will not, apparently, race car drivers have to to tap the brakes if they lift a wheel in a corner. But the odds of losing all traction for one wheel are slim so you'd probably be fine with one in a muddy field. Many people like the helicals because there are fewer wear parts. But the wear parts on a Traction-Lok are easy to maintain.

You have to remember to turn the E-Locker on and off. So you'll want your control button in easy reach. But it would probably make the difference to get you out of a flat muddy field. Not so useful when driving over bumpy muddy terrain. I don't know why Ford switched to E-Lockers. Probably for people driving on flat snow-covered roads.

All three of these need extra care in the slippery stuff. If both back wheels slip, the back of the truck can move side to side. If you're not used to it and ready you can slide sideways and bang in to trees, curbs, or other vehicles.

No offense to differing opinions. These thoughts just came to mind.

jp360cj

That is not correct. The Trac Lock is simply a clutch based limited slip. Just like an open diff, it always sends power (i.e. Torque) to both tires. An open diff has a 1:1 torque "bias" meaning that it always sends the same torque to both tires. Most clutch limited slips usually have around a 2.5 torque bias. If you pick 1 tire off the ground, the LS usually won't be able to overcome the torque differential between the tires.

Saying "the common helical" is misleading. Clutch LS are much more common than helical LS. In fact, the only helical LS I know of are the Trutrac and Torsen.

I don't if it's true, but I've heard that the switch from LS to E-locker was related to the traction control systems. Supposedly they don't work as well together or something like that. I know the newer JKs are similar in that the electronics don't play well with full time lockers, so selectables have become very popular.