SPE Full lock diff kit

funnyman3000

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I saw this product mentioned in another thread. I was wondering how necessary and how safe of a product it is? From what I understand the rear locker disengages after 20mph and this product keeps it engaged. I know Jeeps and Raptors can go past 20mph fully locked, but is it safe for the Tremor? Is it unsafe and result in parts failure, or is Ford just being overly cautious?

 

Chris21667

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following.... i don't know much about the rear locker but i don't see why you couldn't but who knows
 

andrewstclair

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you get more grip because obviously both tires lock instead of the usual one tire fire and that won't be unsafe on its own when you do lose control it is way harder to get it back under control with the rear locked especially when on deceleration. it also increases the chances of losing it because usually one tire may spin but one stays in contact with the road so the back end stays on track for the most part. off-road it doesn't't matter so much but on the street like in rain or snow its dangerous and your better off leaving it where it will disengage. i run 1.5 way limited slip differentials in my cars for this reason, full lock on acceleration but it won't fully lock and toss you sideways on decel. locking it full time if similar to those drift idiots welding their diffs solid.
 

Klutch

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I have one but should have checked with them before ordering. The wire colors on my 2020 don't match their instructions. Waiting for their reply email to see if they have installed one on a 2020.
 

SVT4X4

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I have one but should have checked with them before ordering. The wire colors on my 2020 don't match their instructions. Waiting for their reply email to see if they have installed one on a 2020.
Have you heard back from them on getting this to work on your truck?
 

Loshad

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If putting that on doesn't void your warranty then nothing would.
 

Cybermig

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Diff lockers are traction aids and are usually most effective at slow speeds (crawling, stuck in mud, cross-axle situation). I personally have yet to experience a situation where I would need a locker at >20MPH and that's after owning a vehicle (prior to the Tremor) that had 3 lockers in it (front, center, rear). Then again I've never owned a Rock Bouncer or Ultra4x4 and tried to send my vehicles up steep climbs or rock gardens at >20MPH where a locker engaged at that speed is advantageous.

Since momentum is obviously a factor when at speed, usually any loss of vehicle momentum is typically handled very well by the vehicle's traction control system and or LSD.

Some people just want to have their lockers on command which I can respect but I have yet to run in to the "need" for this kit. The ford AdvanceTrac setup and our off-road terrain traction control is quite good when put in the proper settings.
 

Apparition

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I've never had a need for a locker on the road. Lockers are bad news in slick onroad situations.

I don't offroad baja style with the lockers on in either of my vehicles.
 

Smindustries

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Diff lockers are traction aids and are usually most effective at slow speeds (crawling, stuck in mud, cross-axle situation). I personally have yet to experience a situation where I would need a locker at >20MPH and that's after owning a vehicle (prior to the Tremor) that had 3 lockers in it (front, center, rear). Then again I've never owned a Rock Bouncer or Ultra4x4 and tried to send my vehicles up steep climbs or rock gardens at >20MPH where a locker engaged at that speed is advantageous.

Since momentum is obviously a factor when at speed, usually any loss of vehicle momentum is typically handled very well by the vehicle's traction control system and or LSD.

Some people just want to have their lockers on command which I can respect but I have yet to run in to the "need" for this kit. The ford AdvanceTrac setup and our off-road terrain traction control is quite good when put in the proper settings.

My experiences echo yours. If the three-locker vehicle you're referring to is a G, that's probably why we have similar experiences (had a G500, still have a G55). Those trucks are big and heavy, and can creep over obstacles in a way that seems to mystify Jeep owners.

I feel a lot of it comes down to lockers, weight, and the truck's inherent lack of flex. They just hunker down and put a ton of weight onto the tires, relying on the weight's impact on friction, mechanical grip, and lockers to chug along. Once over the obstacle, unlock the front and steer. If the turn is tight, unlock the rear, too.

There's zero need for lockers on the street at any speed. They're inherently dangerous because people don't have enough experience with them off-road to respect their danger on the street. I don't want my truck dancing around a bend at 35 MPH like an old-school drag car because the rear is locked.
 

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you get more grip because obviously both tires lock instead of the usual one tire fire and that won't be unsafe on its own when you do lose control it is way harder to get it back under control with the rear locked especially when on deceleration. it also increases the chances of losing it because usually one tire may spin but one stays in contact with the road so the back end stays on track for the most part. off-road it doesn't't matter so much but on the street like in rain or snow its dangerous and your better off leaving it where it will disengage. i run 1.5 way limited slip differentials in my cars for this reason, full lock on acceleration but it won't fully lock and toss you sideways on decel. locking it full time if similar to those drift idiots welding their diffs solid.
In a light mustang this could be possible. In a heavy super duty, a full time locker in the rear is no issue. I had one in my 2007 F-250 (Detroit locker rear/truetrac front) in Minnesota for almost 14 years. I also had detroit lockers front/rear) in a 2004 F-250.
Lockers are the ultimate traction in a heavy super duty, rain, snow, mud, ice, dry...does not matter
 

Apparition

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In a light mustang this could be possible. In a heavy super duty, a full time locker in the rear is no issue. I had one in my 2007 F-250 (Detroit locker rear/truetrac front) in Minnesota for almost 14 years. I also had detroit lockers front/rear) in a 2004 F-250.
Lockers are the ultimate traction in a heavy super duty, rain, snow, mud, ice, dry...does not matter
If I were to use my ARB's on a slick road my vehicle would want to go sideways because of the crowned road. You don't want a locker engaged on slick surfaces. An auto like a detroit likely isn't doing anything while on road.
 

Smindustries

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If I were to use my ARB's on a slick road my vehicle would want to go sideways because of the crowned road. You don't want a locker engaged on slick surfaces. An auto like a detroit likely isn't doing anything while on road.

A Detroit Locker is a 'locker' in name only. It still biases and adjusts power delivery.

https://www.eaton.com/us/en-us/products/differentials-traction-control/aftermarket-differentials/detroit-locker-faqs.html said:
The Detroit Locker is an automatic locking differential. This means it is normally locked during straight-line driving and sends 100% of the available torque to both wheels equally. During turns and maneuvers, the internal components unlock to allow one wheel to spin faster or slower as necessary (free wheel). When the vehicle returns to straight-line driving, the components re-engage and provide equal power to both wheels.

A Detroit Locker should be called a 'Detroit Limited-slip'.
 

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Modern traction control systems are amazing. Had a new Volvo a long time ago that had one of the first systems. It was full time AWD. It also had a 'Get Outta Jail' button, for lack of a better description. We were heading up I-70 in UT doing my usual 80. Headed into a downpour heading up a big hill on a curve. In the downpour I backed off from 80 down to 65-70. As I started to pass a semi I guess we started hydroplaning and drifting towards the trailer. I thought we might just fit beneath it but I hit the 'Get Outta Jail' button instead and it was instantaneously like the car was on railroad tracks! I kept my foot in it and kept on keeping on.
 

Smindustries

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True but when it locks your ass can pass you

'Detroit Limited-slip Sometimes-spin'?

I kept my foot in it and kept on keeping on.

This is where people screw up, and screw up big time. I used to work for an outfit training emergency personnel in a vehicle called a 'skid car'. Basically a car on casters that I could get to do anything in an effort to throw off the student.

One of the things we had to drill into people is that, yes, modern traction control systems are amazing, and much better at car control than drivers. The catch is that you have to let the systems work. Drivers have a tendency to jump off the throttle when things go wonky and the traction control intervenes, without realizing that if you're not applying power, there's no slip, and the system goes back into passive mode.

When traction control systems intervene, the driver has to to keep their foot in it for the system to work. The system is making corrections based largely upon the driver's input. When the driver starts some erratic on-off-on-off throttle shit thinking they're really working it, they're screwing themselves. The average person can drive a car around a circuit with full traction control on, pulling power and braking individual wheels much faster than they can with those systems off. The vehicle needs to know the intended direction. Keep the wheels pointed where you want to go and let the computers figure everything else out.

In short, good on ya. You did the right thing keeping your foot in it. It's counter-intuitive, but it works.
 

Loshad

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Well, I gots racing genes in the family in England. Like big time. I've never done any organized racing but been schooled by the best in cars with Seat Of The Pants traction control, as in none. Cars are also much like aircraft - don't do anything radical unless you're absolutely sure that it's called for. At least in aircraft being upside down isn't necessarily a bad thing. :)
 

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Well, I gots racing genes in the family in England. Like big time. I've never done any organized racing but been schooled by the best in cars with Seat Of The Pants traction control, as in none. Cars are also much like aircraft - don't do anything radical unless you're absolutely sure that it's called for. At least in aircraft being upside down isn't necessarily a bad thing. :)
tenor.gif
 

Smindustries

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Well, I gots racing genes in the family in England. Like big time. I've never done any organized racing but been schooled by the best in cars with Seat Of The Pants traction control, as in none. Cars are also much like aircraft - don't do anything radical unless you're absolutely sure that it's called for. At least in aircraft being upside down isn't necessarily a bad thing. :)

The best driving instructor I ever had was a former Tomcat pilot and naval instructor. I asked, "Cars must be pretty easy compared to airplanes, right?" He replied, "Oh, hell no. Not having that Z-axis is a bitch. Things happen much faster in a car. Airplanes can fall a long time before hitting something. In a car the penalty for failure is severe and immediate."

Pretty much changed my whole perception.
 

Loshad

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LOL Altitude and airspeed are your best friends! You can trade one for the other to suit the situation. But you can run out of both in a hurry. Then you're in trouble.

Apparition, search YouTube for the Boeing 707 barrel roll.
The head test pilot was doing a flyby with the prototype at the annual Sea Fair during which the international association of airlines was also having a convention. The new plane's sales were very poor at that point. He did a unscripted barrel roll at about 3000' above Lake Washington in front of 200,000 people!
By the time he landed the orders were pouring in! Legend!

FYI, a barrel roll is a very simple 1G maneuver that puts zero stress on the airframe or engines. Some recip engines don't like it but jets don't care. A C-5 Galaxy could do one but then its pilots would be looking for new jobs.
 
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