F150 3.73 locking differential

[DCBoost]

I have a question regarding the 3.73 locking diff. I realize you have to push a button to "lock" it in, but how does it behave when not "locked"? If there's any rear wheel slippage does it still do anything to transfer power to the opposite wheel when not electrically locked in? Reason I ask is the last trucks I had were GMC's. They had Auto Locking where slippage causes the other wheel to lock in by mechanical means inside the diff. No button. Have to admit, it worked really good, only locked in when necessary. Not a question of which one is better, I have a Plat PB on order - just trying to understand it.

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[Mtnman1]

Only engages with button. Will turn off automatically when you get above 15 or 20 mph...forget which.

 

[IconicXLTsport]

It is an open diff when not locked, same as the GM diff. The truck does have traction control via the brakes to limit wheel spin in normal driving.

The difference is with the ford locker,the driver can lock the diff in slippery situations BEFORE slipping occurs and prevent loss of traction. The GM auto locker has to detect slippage already happening, therefore a loss of traction has already occurred. The ford differential is a mechanical locker, it’s just actuated electronically by the driver.

so if you know you’re about to pull a boat up a slippery ramp or you’re going to go down a slippery trail or driveway, you can lock the differential before any slippage happens and never break traction.

 

[parkerdog]

I have a 3.73 with the electronic locker and I kind of wish I had went with an open dif and then had an aftermarket torsen or something similar installed.

It's just like an open dif without hitting the button. I don't go off road so mine is kind of useless because when I have engaged it and then forgot about it on pavement you get some really noticeable noise on turning corners.

 

[DCBoost]

Thanks for the replies. That was I thought. It would nice if the electric locker portion was added to the GM like mechanical locker. Then, it would engage automatically if slippage was detected or you could choose to "lock it in " by the button. After all, GM and Ford share the 10 speed design ...

 

[Pedaldude]

Some of the off-road packages have something similar to Toyota’s A-trac, where they use the ability to brake individual wheels to approximate front and rear locking differentials. When slip is detected, the wheel losing traction is braked and the torque is sent to the wheel/s that are hopefully getting traction.

The good thing about the e-locking rear differential is that you can get it on pretty much every F-150 4X4 or not and as said before it just locks the rear and doesn’t need slip to activate.

 

[DCBoost]

Good point!

 

[hotrodmex]

The GM auto locker has to detect slippage already happening, therefore a loss of traction has already occurred.

Had no idea that these existed. Interesting solution.

It would nice if the electric locker portion was added to the GM like mechanical locker.

The real business would be a clutch type LSD combined with an E-locker. The e-lock ring is already outside the spider gears, so it's not like you couldn't make this happen. Ther'e's not a lot of room but even a few clutch discs with a low preload would be enough since you have the locker for serious stuff. Everything adds cost, thought.

 

[DCBoost]

I just sold my 2018 Sierra with that mechanical locking diff. The diff locked really quick if a tire broke loose. Good video on it.

 

[IconicXLTsport]

I like the e locker on the fords cause they are very common compared to other trucks. Instead of getting 4wd where I live in coastal North Carolina at a cost of $4000, I get 2wd trucks with a rear locker at a cost of $400 and pocket the savings and the reduced fuel cost. And I still haven’t needed to use the Locker.

 

[Rockman5159]

Thanks for the replies. That was I thought. It would nice if the electric locker portion was added to the GM like mechanical locker. Then, it would engage automatically if slippage was detected or you could choose to "lock it in " by the button. After all, GM and Ford share the 10 speed design ...

last year I think they offered electronic locking or mechanical locking i have the electronic locking 3:73 on mine

 

[notabot]

I have a question regarding the 3.73 locking diff. I realize you have to push a button to "lock" it in, but how does it behave when not "locked"? If there's any rear wheel slippage does it still do anything to transfer power to the opposite wheel when not electrically locked in? Reason I ask is the last trucks I had were GMC's. They had Auto Locking where slippage causes the other wheel to lock in by mechanical means inside the diff. No button. Have to admit, it worked really good, only locked in when necessary. Not a question of which one is better, I have a Plat PB on order - just trying to understand it.

FWIW, I haven't found a real day to day use for the e-locker I've had in trucks over the last 15 years. I did have AWD on a Dodge and now on 2 out of 3 of my last Ford trucks. Your Platty should come with AWD which is the cats meow. Ya dig?

I like the e locker on the fords cause they are very common compared to other trucks. Instead of getting 4wd where I live in coastal North Carolina at a cost of $4000, I get 2wd trucks with a rear locker at a cost of $400 and pocket the savings and the reduced fuel cost. And I still haven’t needed to use the Locker.

I spend a bazillion dollars more than that on insurance premiums to have them and not need them. Watching my brother get stuck on a greasy, nearly flat road in his 4x2 pickem-up truck was enough to convince me to always-always buy 4x4, where available.

FWIW, I much prefer AWD...

 

[IconicXLTsport]

Insurance is required by law and your financier. 4x4 is not lol.

I would have 4x4 if I lived elsewhere. Used to live in Indiana and it’s hard to find a new truck that is not 4x4 there aside from work trucks. Where I live and with what I do, I don’t need it and it saves me considerable cash to not have it from the deal I got on the 2wd truck to the mpg improvements.

I have a 3rd vehicle that is 4x4 if the need arises.

 

[Bryan Simon]

I just sold my 2018 Sierra with that mechanical locking diff. The diff locked really quick if a tire broke loose. Good video on it.

my 98 k1500 has lockers front and rear.
In 2wheel, that rear locks in a hurry.
Sometimes on dry pavement just making a hard right or left (chirp chirp chirp).
Heavy sprung pickup on wet roads during a turn can be exciting to say the least.
Rear tries to pass the front on a turn from a light. Halfway into the turn, the rear locks, then tries to escape.
The upside is, when I need or want 4x4, all 4 dig like there is no tomorrow .

 

[Calson]

Having the locker off when not needed reduces wear and tear of the components for longer life. Most of the time I do not need the locker engaged and when I do want it then pushing a button on the dash could not be simpler. Check the manual for more information.

GM no longer provides a locking or even a true limited slip differential (nor does Toyota) and instead what they provide is an "anti-spin" differential and what happens is the brake is applied to the faster spinning wheel. Often called traction control with 2WD rear drive cars.

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