Base Model Rear Locking Differential

[rtaylor]

I was under the impression that the base 4x4 would have front and rear t-loks or equivalent (automatic mechanical locking of both axles when slippage occurs on the powered wheels).

Please, please don't feel me that a base 4x4 only has one wheel driven in the rear and one in the front? That wouldn't be "4"x"4".

Sorry, the base does not include limited-slip or locking differentials. They are "open differentials" meaning that the front wheel with least traction and rear wheel with least traction will turn. HOWEVER, there is some computer assist to apply brakes to the spinning wheels and approximate the effect of a limited-slip in some circumstances.

Sasquatch will provide full locking differentials, which ensure that 1, 2, 3, or 4 wheels are driven based on the settings. But they disengage above ~20mph so they are for low-speed trail use, not high-speed offroad.

For the Raptor-ized Bronco in development, it likely will have a limited-slip in the front and e-locker in the rear for better high-speed offroad and street performance. With this setup, you apply brakes and throttle simultaneously in situations when full front traction is desired.

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[qnet]

Thanks to several for the responses as this has been on my mind too.

I've watched several videos about mechanically what is happening in a 4x4, AWD, etc. but have still had problems understanding some truck stuff here. (I was a car guy in the past and even swapped rears (gears, t-lok) for a Mustang so I have a general background)

I was under the impression that the base 4x4 would have front and rear t-loks or equivalent (automatic mechanical locking of both axles when slippage occurs on the powered wheels).

Please, please don't feel me that a base 4x4 only has one wheel driven in the rear and one in the front? That wouldn't be "4"x"4".

I do understand what a locker is and its use. I MAY want a rear locker but that's it. I definitely would want a t-lok or equivalent in both differentials.

The previous poster before described it best IMO. I had the same thoughts as you until I looked it up, and read about it.

All wheels would be driven - in a 4WD automobile when engaged - on a surface with equal traction. It is in fact 4WD on the base. Having said that, with an open diff; it sends more torque to the wheel with the least resistance, thus a slipping wheel would get all the power sent to it.

This was another reason I wanted to stick with the BB vs. the Base, to be able to add the rear locker. I may never need it, but it would be nice to have, just in case.

I wish Bronco had at least limited slip diffs on both axles. They could have that but from what we all know they don't.

 

[Rocketeer Rick]

Unfortunately, Ford seems to have moved away from LSDs as a philosophy, at least in trucks. On my 2013 F150, you could upgrade to either a Traction-Lock or a locker. But starting in 2015, they did away with the Traction-Lock. Maybe it was a take rate thing, maybe they thought lockers were more marketable, maybe they figured that traction control was good enough, who knows. But that has extended into all the truck lines. I think the helical LSD in the front of the Raptor is the only exception these days, and that more based on the specific use that truck was designed for.

The move to welded ring gears is occurring across the industry, unfortunately. Its a cost savings, plain and simple. GM went that way with Camaro in 2016, so those guys are dealing the same thing. At least with the Dana axles in the Ranger/Bronco, there are bolt-on versions of the same axle model in production, so you guys can at least buy bolted ring&pinion sets to swap in if you want to diff swap or regear later...

 

[DonM]

Rear differential locker is the only option I'd like to have available for my base model. It doesn't look like Ford is offering it for the Base model. Because the rear locker will be electronic and it looks like the base uses the same differential as other models, do you think Ford will off an aftermarket option for the electronics to convert to a locking differential? Any thoughts?

Maybe jump up to the Big Bend? Gives rear E-Locker in 4.27 gearing. I'm contemplating this option as I don't really want the 35's either. The Big Bend tires fit into an okay space for me and my overall likely use. With the E-Locker and gearing change, the 2.3 with Auto and the upgraded T-case might be my best setup.

Plus I'm still holding out for a better tow package that I believe would be perfect on a BB or OBX.

 

[ric42pars]

Thanks for all the excellent information. Still unsure of what I want to do but I appreciate all of the background information. I will be getting a 2 door/manual and the jump of $5-8K on the BB or BD is hefty so I'll need to evaluate that verses just adding a locking differential some day.

 

[FrogGrabber]

Brake lock distribution is a traction control for off road use that applies brake to spinning wheel (one wheel drive) which allows other wheel that has traction to spin. It actually works quite well in most situations. Not as good as a mechanical locker, but still good. It’s on every bronco (and every wrangler).

 

[EvlNvrDys]

Just do the aux switches and wire it up. Dana 44 m220 rear has every locker option under the sun.

(Just keep in mind you’ll still have the weaker front dif; I’d hesitate to run anything larger than 33’s on it)

+1
As said, stay under 33"s.

Chevy has a factory locker in its M190 on the ZR2.

ARB is about to release a M190 locker too.

Help me out fellas... Like I've stated from the beginning, I come from 3 FSB's. And back then, if you wanted 35's, you put a lift and 35's on. We didn't care about what gears were in the rear, didn't care if this diff was a "lower end" (because I believe they were pretty much all the same back then).

So if I go away from the Squatch package, start out with 33's and eventually switch to 35's, will the M190 be an issue? This Bronco won't be crawling rocks or anything like that. It'll maybe see some trails here and there, but nothing aggressive. So do I need to worry about that?

 

[Incognito]

Help me out fellas... Like I've stated from the beginning, I come from 3 FSB's. And back then, if you wanted 35's, you put a lift and 35's on. We didn't care about what gears were in the rear, didn't care if this diff was a "lower end" (because I believe they were pretty much all the same back then).

So if I go away from the Squatch package, start out with 33's and eventually switch to 35's, will the M190 be an issue? This Bronco won't be crawling rocks or anything like that. It'll maybe see some trails here and there, but nothing aggressive. So do I need to worry about that?

As long as you keep your offroading tame, 35"s will be fine.

The vast majority of Jeeps you see rolling on 35"s , have the very weak D30 front axle.
Only the Rubicon comes with a D44 front that can handle 35s and some rough treatment.

The M190 in the Bronco has a higher torque rating than the D44. But the M190 is a IFS, so it's not an apples to apples comparison.

Just keep on mind that Ford only went up to 32" tires on the Black Diamond and the M190.
And they kept the front open.

The Badlands went with the M210 for the 33"s and a locker.

Consider those tire size cutoff points for vehicles that will see rough treatment, with/without a locker.

We're not going to know how conservative Ford was with choosing axles and lockers until people get out there and start breaking things.

 

[Nickp]

Help me out fellas... Like I've stated from the beginning, I come from 3 FSB's. And back then, if you wanted 35's, you put a lift and 35's on. We didn't care about what gears were in the rear, didn't care if this diff was a "lower end" (because I believe they were pretty much all the same back then).

So if I go away from the Squatch package, start out with 33's and eventually switch to 35's, will the M190 be an issue? This Bronco won't be crawling rocks or anything like that. It'll maybe see some trails here and there, but nothing aggressive. So do I need to worry about that?

A wrangler Dana 30 gets a bit sketchy with 35’s if you wheel it hard, but is fine if you don’t off-road that hard. I would say that if you aren’t wheeling hard the Dana 30 front would be fine, but if you intend to put those 35’s to work probably wouldn’t be ideal. Also, having an open dif helps because there is a lot of strain put on components when lockers get involved, so that is one good thing with the Dana 30 front.

 

[BearWithMe]

If the Sasquatch package is indeed only $5,000, it's a helluva deal. Upgraded front diff, front diff lock, rear diff lock, upgraded resi shocks with extended travel, 4.7 gears, and (I think) the "advanced" T-case with AWD and lower crawl ratio.

If you don't want the 35s and the ugly wheels, sell them. People love beadlocks...

 

[ric42pars]

Hmm. Found something interesting when doing a build & price tonight. It looks like the base has the same differential axle ratio as the standard Badlands and Black Diamond automatics. Both have locking differentials standard no matter the transmission. Coming from a manufacturing company myself, we try to commonize parts as much as possible. Will this differential on the base-manual just need some electronics to make it a locker. Any thoughts?

 

[ric42pars]

Compare it to what it says here for the base-automatic where it clearly states open differential.

 

[da_jokker]

I have no idea but noticed in your pic that it states "...locking differential shown" so would that account for them looking the same? (Because they are)

 

[Rocketeer Rick]

My $0.02 - the fundemental differential will absolutely be different between the open and locker; they will be different differential carriers, made from different castings. My perspective comes not only from being with a manufacturing company, but one that actually builds differentials (though not these diffs).

The open diff is a very simple mechanism, and will have a very pared-down carrier. It'll be just enough to get the spider gears into it and have the needed strength for the axle's rating. Anything more than that adds cost, and Dana will be building 100s of 1000s of these a year, since they sell them to other customers than Ford. There is no need to add anything not required, and they're doing enough volume to justify different tooling needed to make different versions.

The locker, OTOH, will need a carrier that has unique features that open won't have - it'll have to accommodate the magnetic coil that actuates the lock, it'll have to have provisions to the lock's dog clutch, and it might even a different set of spiders gears to make room for the other stuff. So it will absolutely be a different carrier than the open model. And it goes without saying that if the diff carrier has to accommodate all those parts, it has to have those parts too. That is all extra cost that would only be added if needed.

Again, at the volumes that we're talking about here, making different versions is no big deal. They will need multiple sets of tooling to meet the overall volume anyway, so its no problem to make them different.

Where they might have a common link is the outer carrier, the "pumpkin" housing that contains the diff and ring & pinion. This is likely to be a common casting, with the only machining differences being a port for the e-locker's wiring. But that doesn't buy you a lot if you can't remachine it yourself to allow for an aftermarket wiring harness.

So, short version: if you buy a truck with the open diff, you will have a stictly-speaking open diff. It will not be able to be turned into a locker with just some wiring.

 

[tokyo]

I plan on adding a Truetrac lsd to a base.

I like this idea as I want to keep the 3.73 gears.

I do 85+ MPH on freeway a lot and will stay at 33's so don't really need the 4.27 gears that the option comes with when stepping up to BB.

I had a helical LSD on a Hemi Ram1500 and the current e-locker on my F150 and they both fill my needs fine.

I love my current 2.7, A10, 3.73, 33's with e-locker combo..