Ford Factory E-Locker Teardown (and some discussion)

[david85]

I might ramble a bit here, so apologies in advance.

Many of us are tempted by the thought of a used Ford E-Locker, since they could prove to be a much more cost effective option than going to a brand new aftermarket E-Locker. Used parts are usually cheaper, after all. And we've all probably seen videos and forum discussions all over the web that let the secret out; it's backward compatible on the sterling 10.25. So no need to perform a full axle swap!!!

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One problem though. The aftermarket E-Lockers that I have seen are not what I consider to be a very good design. The Eaton E-locker shown below uses a cam mechanism to perform the actual lockup. The result? A locker that can in theory unlock when changing from forward to reverse or vice versa. These folks seem pretty proud of it and downplay this problem, but I wasn't convinced. Which is why I never did buy an aftermarket E-Locker, even before finding out the factory Ford unit existed:

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Air lockers are usually direct acting, meaning the actuator directly engages the splines to lock the spider gears. Better than the Eaton E-Locker shown above, but now you have to run air on board. Which can be nice anyway, but it's one more system that adds to the cost if you don't already have it in your truck.

Ox lockers have a mechanical cable actuator and a shift fork. It looks pretty robust, but adding two more shift levers to the floor seems a bit much.

As luck would have it, one of these mythical Ford E-Lockers showed up on marketplace 5 min from my house. So naturally, I jumped at it. Does it use a cam-lock mechanism like the Eaton? Don't know. In fact, I couldn't find any photos on the web of somebody taking one of these things apart. Plenty of conversions done, but no details on how it actually works. No exploded drawings showed up on image search, either.

So what to do? Pull mine apart, of course!

First off, remove the eight metric bolts. Note the red thread locker:

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Next, remove the top and we see the three pinion spider setup. Pretty simple stuff so far:

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The 3-pinion shaft also acts like a locator dowel for the two halves, so no need to worry about centering issues of the carrier. Simply scribe the case before taking it apart to maintain the factory clocking.

More to come...

 

[david85]

Alright, just one gear left to go. This setup seems to be retained by a snap ring. I've seen retaining systems like this in my E4OD transmission so nothing exotic about this. The gap in the ring is clocked to be safely secured in the groove, rather than free floating between the ribs. Pretty standard stuff.

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Snap ring removed to reveal a solid plate:

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Remove the solid plate, and now we have a spring plate. Yup, make sense. Also starting to see what looks like radial splines. Getting closer.:

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Okay, all the retaining rings are removed:

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More to come...

 

[david85]

Here we finally see the actual locking element. Radial spines (not sure if that's the right term, but I'll use it) on the back of the gear engage with a matched set on the locking plate. The locking plate then engages on the inside ribs of the carrier. All still very simple:

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By the way, that last gear can be removed even before pulling the retaining rings. I realized that later.

Below we see the locking plate fully exposed. Those spines don't look very deep, but the total area is fairly large, so maybe it doesn't matter. The semi-tangentially aligned oil grooves are an interesting feature as well. I'm used to seeing thrust washers with radially aligned grooves but this is a new one for me:

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The next two photos show the locking plate in the retracted and deployed positions. I'm simply moving the solenoid body by hand in this case:

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We still haven't seen how the actuator works though. Is it direct acting? or does it use a cam mechanism? More to come...

 

[david85]

Aha! Okay, so now we see three machined rods that engage the rear of the locking plate. No cam mechanism here:

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Next two photos show the pins in their retracted and deployed positions. Again, this movement is done by hand by pressing the solenoid into the side of the carrier:

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So it's confirmed. The solenoid actuator is direct acting on the Ford unit. No cam-actuator mechanism, and no risk of the locker releasing if you have to rock the truck back & fourth while engaged. I like it.

We can also see how much simpler the overall design really is. And we can also see how the locking splines could get stripped fairly easily if one were foolish enough to engage the locker during a "one tire fire".

Lastly, I opted to get the ford OEM connectors for a factory style hookup. I don't know if I'll do any river crossings in this truck, but I don't want water getting in through the wires. Or oil leaking out, for that matter:

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Overall, I'm happy with the purchase. I don't know what I'll do for a front locker. E-Locker is still my preference but who knows when that will happen. For now, I'm thinking to install one of these Toyota Land Cruiser locker switches right next to the glow plug light for a nice OEM look. It would also be conveniently located near the transfer case lever:

FJ80 / FZJ80 80 Series Land Cruiser Diff Lock Switch

Genuine Toyota differential lock switch. This switch came factory on Elocker equipped 80 Series Land Cruisers. Many people use this […]

www.yotamasters.com

When will this all happen? Who knows! But based on how long it took for me to complete the 4wd swap, it won't be quick: https://www.oilburners.net/threads/dana-60-going-in-eventually.86730/

At least now we all know what's inside a factory Ford E-Locker

 

[Double-S-Diesel]

awesome write up
that is what i have in my truck from the factory.

 

[nitroguy]

Wow, phenomenal information. Thanks for your work documenting this. Looks like a great upgrade!

 

[TNBrett]

That was very nicely done. I agree on your concern with engaging while spinning one tire, or even under power at all. I’m sure the computer wouldn’t let that happen in the factory installation. Perhaps you could wire it up with a relay in a latching configuration that could only be engaged in neutral, or with the clutch engaged.

 

[lotzagoodstuff]

Top notch write up David85 . If the border was open, I'd drive up and buy you a two four of Kokanee to celebrate the successful conclusion of your factory E-Locker investigation confirmation

Just wondering: being that you bought your unit used, did you get any history on mileage, lubricant, service history versus what it looked like inside? I thought the pics looked pretty spotless, and I wouldn't expect any debris from the engagement mechanism, but that's speculation.

Lastly, I considered buying all the parts brand new as they are pretty hounded by the offroad folks as soon as they show up in the salvage yards down here (read expensive). What's a ballpark price on a used unit up there in BC?

 

[david85]

That was very nicely done. I agree on your concern with engaging while spinning one tire, or even under power at all. I’m sure the computer wouldn’t let that happen in the factory installation. Perhaps you could wire it up with a relay in a latching configuration that could only be engaged in neutral, or with the clutch engaged.

I'm actually not too worried about it in my case. Shifting a manual transfer case requires some precautions as well, so I don't see much of a difference here. If you had ABS sensors are each wheel, then you could use a small electronic controller that uses a frequency matching logic as an engagement permissive. I suspect this is how Ford does it from the factory....but that complicates things since our trucks don't have these sensors at the wheel. Some kind of an interlock tied to the neutral safety, clutch, or even a zero speed switch that looks at the VSS output could certainly work as well. This would act like an engagement permissive, but allow the locker to remain on if it was already engaged.

A bit complicated, but doable. I don't think it would be a big issue to engage while driving in a straight line on solid ground though.

Top notch write up David85 . If the border was open, I'd drive up and buy you a two four of Kokanee to celebrate the successful conclusion of your factory E-Locker investigation confirmation

Just wondering: being that you bought your unit used, did you get any history on mileage, lubricant, service history versus what it looked like inside? I thought the pics looked pretty spotless, and I wouldn't expect any debris from the engagement mechanism, but that's speculation.

Lastly, I considered buying all the parts brand new as they are pretty hounded by the offroad folks as soon as they show up in the salvage yards down here (read expensive). What's a ballpark price on a used unit up there in BC?

Here's the history on the unit, according to the guy that sold it to me. It was a nearly brand new truck and the he didn't like how the locker is disabled above 40 km/h. So rather than do his research and look for a software mod (which I think is well known these days), he ended up paying a shop to install an air locker. Not the smartest thing on his part when you consider what a new superduty costs these days and the risk to his warranty. But money was clearly not much of a concern to him and I got a locker out of it so who am I to judge?

As for used prices in the wreckers? Well, I haven't made any big purchases for a couple years now. I generally search classified listings for what I need these days. So I am making a big assumption to say that it would be cheaper at the wrecker...but usually parts are cheaper used than at the stealership. Having said that, many online discussions have pointed out prices in the $500-$600 USD range for some new listings direct from some larger Ford Dealerships:

BC3Z-4026-B - Differential Assembly - 2011-2019 Ford | Eastgate Ford Parts CA

2011-2019 Ford Differential Assembly - bc3z4026b. Genuine Ford® Parts & Accessories. Manufacturer Warranty. From the Dealership to your Door. Experts standing by.

www.eastgatefordpartscanada.ca

I never asked at the local dealership because prices in Canada are usually crazy compared to stateside. So again, I'm only assuming here.

 

[ocnorb]

Thanks for spilling the guts on these! I have one in my shop ready to be installed. I already installed the Eaton dash switch and wiring to the rear axle.

Very insightful. The locking mechanism reminds me of the “lunchbox” lockers. Only with an actuator.

 

[YJMike92]

Thanks for the write up. Sounds like a very viable upgrade.

 

[david85]

I'm really liking the simplicity of the design.

The only thing I can think of that might be a disadvantage over the cam locking style is that you have only the solenoid itself to hold the lock engaged. The cam-lock on the other hand, uses a wedge to hold metal to metal against the locking mechanism. It also allows for longer travel of the mechanism, so you can have more tooth engagement. So you would need an absolutely extreme amount of stress to overcome the locking mechanism, once it's engaged.

Ford (Sterling, I guess) opted to use a higher density of teeth arranged in a radial spline pattern (much harder to machine, actually), which does spread the load fairly well. The ford solenoid also appears to be quite massive, so maybe there really is enough force from the magnet alone to hold the locker engaged. Either way, I'm going with it!

 

[Double-S-Diesel]

fwiw it holds up the hp and torque of the 6.7

 

[Noiseydiesel]

Didn't know Ford had an E-Locker. I went with the Eaton True-track in the rear and the Eaton E-locker in the front Dana 60 diff. Looking at the Eaton E-locker during installation, i can appreciate the simplicity and also see the limitations of that unit. For my asphalt 4X4 dually, it should work just fine.
If I was going bouncing off road, an air locker would potentially be a better way to go.

 

[Noiseydiesel]

By the way, this is a great write up! Thank you!