OEM 9.75" E Locker Retrofit

[Hauk]

I currently have a 2021 RWD 3.5 EB with a 9.75" open diff. I use this to launch ~7000lb boat. It typically does just fine, but sometimes if the ramp is wet/slick, I have to be particullary careful to prevent wheelspin. I am afraid that sooner or later I am going to get in a bind, so want just a little more traction available, for peace of mind. This is my only use case for needing more traction and do not go off road.

With this in mind, I think I would prefer a factory e locker, and would like to get it as close to "stock" as possible. I know alot of people despise the factory e locker, but I think it will be sufficient for my rare use purposes. The ford e-lockers are also more affordable than aftermarket, and can be had for around $400 new. My truck has the green plug and wiring where you would plug the elocker in. I will have to drill a hole in my rear end case to install the connector bulkhead to hook up the e locker solenoid wires. At this point if I have to, I can hook up a toggle switch directly to the solenoid circuit to engage the e lock, but I would prefer to have a more OEM solution. Does anyone know what else would be necessary? Would it be just buying the new drive mode selector knob, pinning the connector and doing some ForScan coding, or is this more involved?

Sponsored

 

[Blueshound]

Without doing any research, I think if the applicable control module is the same part #, you may be okay with just swapping / adding parts. Somebody here probably knows or can find out. Good luck!

 

[Hauk]

Well I think I may have answered my own question. The e locker solenoid circuit is energized by the transfer case control module (TCCM). I'm guessing only 4x4 and RWD trucks with the e locker would have this module. If the connector is already pinned for this module it may be doable, otherwise I think I'm going to just hook up a manual switch to energize the solenoid.

 

[Blueshound]

You could maybe go with a LS diff, no wires needed

 

[Capt Obvious]

Well I have no input for your solution but I am happy that for the most part you are fine with launching and more importantly pulling out a 7k boat. I may have over thought that same scenario and opted for the 4x4 with an e-locker just in case. If you’re doing ok now then I would think that a locking diff is all that one would need.

 

[Hauk]

Yes, I am just really wanting a little extra insurance. I'm now debating between the oem elocker and just an aftermarket lsd such as a true track. If I can't have a stock setup easily with the elocker, then just dropping in a mechanical lsd is pretty tempting because of the simplicity of it. No wiring, no drilling my axle case, etc.

 

[amschind]

I would advise you to strongly consider a torsen like the Eaton Truetrac. I'm actively working to replace the open diff in the front of my truck with a torsen, and used them front and rear on my last vehicle (an old Exploder that with no 2H mode....so it was ALWAYS in 4A). The rear torsen actually chirped less than the garbage stock Ford LS diff that it replaced, and the front was invisible until it was needed. It has no clutches, no air nor electric wires, operates automatically and instantly, and will outlast the rest of the vehicle with even passable maintenance. It IS NOT a locker, but nor is it a limited slip: it biases torque to the wheel spinning slower. This means that if one wheel loses ALL traction, it will spin that wheel like like an open diff. The solution to that issue is to slightly apply the brakes, which provides enough resistance to engage the torsen, at which point it functions better than a locker.

I would advise you to look at the bias ratio carefully, which determines a lot of how a torsen feels. While my front Truetrac was undetectable even with permanent 4A, the Raptor Forum has an ongoing and nasty debate about how the front torsen in that vehicle feels (with some claiming they can't feel it and others claiming that it makes the Raptor drive like an Abrams). In the back only it shouldn't matter, but I mention that only to warn you that the bias ratio number is important, variable between torsen diffs, and determines a lot about how the diff feels.

Anyway, hope that helps.

 

[Hauk]

Thanks for all the advice. I am leaning towards the Eaton Tru track. Does Eaton offer different models that have different bias?

On another note, I made some progress on the stock elocker research. It turns out that all the wiring and connectors are in place for the TCCM. For reference for anyone looking the two connectors are inserted in a blank cap on the top mounting stud where the TCCM should be if it was equipped. This wpuld be a pretty easy retrofit. Basically, you would need to install the e locker diff. Drill a hole in the axle housing for the wire bulkhead, install a TCCM, and then install a drive mode knob (ATCM) with the elocker button, and you are done. Probably about $600 in parts.

Sponsored