23 Non-Sas BB Adding Rear Locker

[Endlessplace23]

Hello,

I picked up a 23 Non-Sas 4-door BB w/ 2.3 and manual transmission. It doesn't have any lockers and I'd like to at a minimum add a rear locker. What would it take to add a locker to this vehicle? Any help is appreciated, thank you.

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[RagnarKon]

So you have two choices:

• Electronic locker
• Air locker

Of those two, I would recommend an air locker. It is more reliable, more robust, and easier to troubleshoot than an electronic locker (a leak in an air line is real easy to track down compared to weird electrical gremlins.). Because an air locker requires an air compressor... you'll also have a means to air up your tires after off-roading.

Under normal circumstances, adding a rear locker simply would require to you open the differential, take out the carrier assembly, swap the ring gear over to the new air-locking carrier assembly, reinstall the carrier... and run air lines from the compressor to the differential.

However, on the Bronco with the open-differential... the ring gear is welded to the carrier assembly. Which means you basically have to rebuild the entire differential. Since you are rebuilding the differential, it also brings up questions regarding rehearing and potentially adding a front locker as well. So it ultimately depends how much money you want to throw at this thing.

 

[SuperDave150]

Currently you have at least 3 aftermarket options:

• ARB air locker
  • https://arbusa.com/air-locker/

• Eaton E-locker
• Eaton Detroit Truetrac
  • https://www.eaton.com/content/dam/e...ormance-differential-application-guide-en.pdf

Personally I like the no-buttons, no-wires, no-air-plumbing simplicity of the Truetrac. Thank the Lord that we live in a free country where you can do what you want.

 

[Digger 5]

I've run Truetracs for years and love them but they are not a replacement for a locker. As long as you understand their limitations you won't be disappointed.

 

[Big Boss]

@Digger 5 care to elaborate more on your experience pros/cons?

 

[Brian_B]

Bumping this as I've been looking into it off and on for a while. I'll start out saying I'm mostly mechanically ignorant, so I'm trying to learn as I go.

I have a BB 7MT, so it has the 4.46. I'm not unhappy with that ratio, it does ok with my current 35's - at least for what I do. But snow is coming... The only time I've ever needed lockers in any vehicle was in snow.

So looking at adding a rear locker, like the OP. Just off the cuff, I'd say I'd skew more towards an e-locker because running a pair of wires to a switch with a fuse is easy and cheap, and a locker isn't anything I'd run for more than a minute or two at a time anyway.

So I understand I need to swap out a ring gear set, and I need to add the locker itself. Trying to work up a parts list so I know everything I need to order

Ford sells the Spicer 4.46 rear ring kit, but they note:
Note: Factory Broncos with 3.73 gear ratio or 7-speed manual equipped have the ring gear welded to the differential and require a new differential assembly to re-gear.

So I can't just open the diff, swap out the gear set, add in the locker, wire it up and go? (I say that like "that's all there is" - it could be extraordinarily difficult, I have no idea, nor what special tools or machining I may need)

I'd love to just find the M220 unit with an ELD someplace and order it and swap it out as a whole, but I don't know that will happen - my luck with finding used parts, that stay working over time, is pretty poor.

Just trying to build up a part list, looks like it would be a Spicer 10145092 gear set (sticks with the 4.46 ratio), an Eaton 14234-1 elocker, and some elbow grease? I think I'd also need the Install Kit, Ford has that listed as this, but I'm wondering if that's the same thing as the 10267429 Install Kit that sells for 1/4 the price?

I don't know the difference between the Spicer Part#, the Install Kit #, or the Master Kit #. I also don't understand how something like an elocker would install to the existing diff housing - or is that why Ford is saying you need a new diff assembly? Just looking at the elocker and the fact that it comes with a bushing makes me think I just knock a hole out near the top of the diff housing to install the bushing?

I see Truetrac mentioned, that may be enough, i don't know, but looks intriquing. I do see this:
2021-2023 Ford Bronco M220 Eaton Detroit Truetrac Limited Slip Rear Differential 917A736
That may do the trick, but I don't know exactly how that differs from a regular locker. It's almost half the price of the elocker, so worth a look at anyway.

Basically, I'm in way over my head here - looking for a bit of help.

 

[orion]

Bumping this as I've been looking into it off and on for a while. I'll start out saying I'm mostly mechanically ignorant, so I'm trying to learn as I go.

I have a BB 7MT, so it has the 4.46. I'm not unhappy with that ratio, it does ok with my current 35's - at least for what I do. But snow is coming... The only time I've ever needed lockers in any vehicle was in snow.

So looking at adding a rear locker, like the OP. Just off the cuff, I'd say I'd skew more towards an e-locker because running a pair of wires to a switch with a fuse is easy and cheap, and a locker isn't anything I'd run for more than a minute or two at a time anyway.

So I understand I need to swap out a ring gear set, and I need to add the locker itself. Trying to work up a parts list so I know everything I need to order

Ford sells the Spicer 4.46 rear ring kit, but they note:
Note: Factory Broncos with 3.73 gear ratio or 7-speed manual equipped have the ring gear welded to the differential and require a new differential assembly to re-gear.

So I can't just open the diff, swap out the gear set, add in the locker, wire it up and go? (I say that like "that's all there is" - it could be extraordinarily difficult, I have no idea, nor what special tools or machining I may need)

I'd love to just find the M220 unit with an ELD someplace and order it and swap it out as a whole, but I don't know that will happen - my luck with finding used parts, that stay working over time, is pretty poor.

Just trying to build up a part list, looks like it would be a Spicer 10145092 gear set (sticks with the 4.46 ratio), an Eaton 14234-1 elocker, and some elbow grease? I think I'd also need the Install Kit, Ford has that listed as this, but I'm wondering if that's the same thing as the 10267429 Install Kit that sells for 1/4 the price?

I don't know the difference between the Spicer Part#, the Install Kit #, or the Master Kit #. I also don't understand how something like an elocker would install to the existing diff housing - or is that why Ford is saying you need a new diff assembly? Just looking at the elocker and the fact that it comes with a bushing makes me think I just knock a hole out near the top of the diff housing to install the bushing?

I see Truetrac mentioned, that may be enough, i don't know, but looks intriquing. I do see this:
2021-2023 Ford Bronco M220 Eaton Detroit Truetrac Limited Slip Rear Differential 917A736
That may do the trick, but I don't know exactly how that differs from a regular locker. It's almost half the price of the elocker, so worth a look at anyway.

Basically, I'm in way over my head here - looking for a bit of help.

Or buy a take off axle like the one sitting in my garage. 4:46 from a Black Diamond. Easiest way I would think.

Heading to San Diego for Christmas and could meet up somewhere if you are interested.

 

[Brian_B]

Following up on this, for posterity's sake. My goal was to leave the front end alone for now, I just wanted a rear locker, so I didn't touch my M190 front end.

In my research, I found there were basically 3 options

Finding a used take-off is the easiest route. That isn't always possible though.

If you are ok with stock gear ratios, Ford sells the rear end with the ELD and it isn't terribly expensive - you get an entire new axle with diff, gears, ELD, and rotors pre-installed and ready to drop in. You just have to be ok with the stock ratios.

The part number for my 4.46 was M4000446B
Similarly, the 4.70 is M4000470B

There is a 5.38 option, it upgrades to a Dana 60 and you definitely need to swap the FDU as well (remember FDU and rear have to have same ratio). The rear part number is direct from Dana: SF-L60BR538E-69 -- Ford has the 5.38 M210 FDU as M-3002-538BF, and Ford Performance Tune supports upgrading the axle to that ratio.

Ford sells a harness and switch for upgrading a non-ELD to an ELD ( M-14489-BR ), but it doesn't go through GOAT modes or anything fancy - it's just a relay and switch. You could just as easily wire it to an upfitter switch using the connector for a lot less cost. The part number for the ELD connector is WPT829.

From what I gather (and I could be wrong, I didn't try it) - if you want a non-stock ratio, or want an air locker or something else - you need a regear shop. It isn't a "do it in your garage" type thing to swap out the gears in the differential. Although I'm tempted to try it on an older car and see how it goes. Pricing on this will vary based on your shop - for my area it was a bit cheaper than an entire new axle, but it wasn't significantly cheaper - YMMV.

 

[climb2descend]

Thought I would add to this discussion since I had been doing some research also, still not sure what I want to do yet. Finding a used 4.46 locker axle is really hard, ive been looking for quite a while and they rarely pop up if ever. 4.70 seems more common if you try to go junkyard route, makes sense since most people seem to be buying sasquatch. But it doesn't even seem like looking at junkyards is worth the time, they want more then a brand new ford performance new axle assy.

Lockers that are available: ARB air locker, Eaton E-locker and Yukon e-locker.

The Yukon e-locker seems cheap at first:
https://www.yukongear.com/shop/yp-pcdm220e-32-a

But it requires new axle shafts, you need these because it has offset cross pin:
https://www.yukongear.com/shop/ya-wdm220-32-308 LH
https://www.yukongear.com/shop/ya-wdm220-32-366 RH

I also looked into just buying the Ford locker carrier assembly(not the whole axle assy), and the non locker and lockers axles have different axle shafts, so you would likely will need the locker axle shafts if you try to swap just the ford locker into your existing axle also so that's not a cheap option either. I dont know what the difference is, but there must be some reason to have different ones.

I also asked OX if their m220 jeep locker would work on the bronco, they said they had not seen it done but think it would work. Feel like I would rather have an e-locker over this one though.

I also explored a bit the helical limited slip route, I thought the Nitro Helix could be a bit cheaper alternative to the Detriot True Trac, but Nitro told me the Jeep M220 32 spline will not fit the Bronco, which doesn't make sense to me, but that's what they said.

Price wise it does seem about a wash between having locker and gears installed in your existing axle vice buying a new ford performance axle assy. Trying to get rid of the whole open axle assembly after you swap a whole axle assembly seems like a pita, so kind of a con going that route.

 

[Brian_B]

I also looked into just buying the Ford locker carrier assembly(not the whole axle assy), and the non locker and lockers axles have different axle shafts, so you would likely will need the locker axle shafts if you try to swap just the ford locker into your existing axle also so that's not a cheap option either. I dont know what the difference is, but there must be some reason to have different ones.

I was actually just about to try this - putting axle shafts from a non-ELD assembly into an ELD assembly. Anyone have any idea what the deal is? Do the shafts have different part numbers?

Partial Answer: Ford does have 2 different part numbers for the axle shafts:

Non-Locking
Left: MB3Z4234H
Right: MB3Z4234AS, supersedes MB3Z4234G

Locking
Left: MB3Z4234F
Right: MB3Z4234E

Aftermarket rear axle show only 1 part (no differentiation between Left and Right), but with a note that other applications may need to "cut to fit"
https://www.offroadwarehouse.com/pr...r-dana-m220-rear-differential-yawdm220-32-366

 

[climb2descend]

I was actually just about to try this - putting axle shafts from a non-ELD assembly into an ELD assembly. Anyone have any idea what the deal is? Do the shafts have different part numbers?

 

[Brian_B]

Glad you pointed it out - now to see if I can figure out what the difference is to see if I need to change plans or not.

 

[climb2descend]

Glad you pointed it out - now to see if I can figure out what the difference is to see if I need to change plans or not.

No problem this was as far as I got. My best bet is the locker and non locker have different axle shaft lengths because it's likely the ford factory locker (made by GKN) has offset cross pin.

 

[orion]

Glad you pointed it out - now to see if I can figure out what the difference is to see if I need to change plans or not.

@Ducati1098 or @flip. Do either of you have axles in stock to see if there really is a difference?

 

[flip]

I don't have any of that in stock. If I had to guess it's going to be spline count, spline diameter or spline length. Leave it to Ford or Dana to come up with a design to maximize the number of unique parts depending on option. They learned nothing from Alan Mulally. Only thing should be different is gear ratio and center section. All the other stuff should be interchangeable.

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