Had a chance to try out the rear locking axle today in my 2020 in a bit of snow/ice, and I'm curious about the behavior I witnessed.

In 2 wheel drive, I purposely got truck "stuck" by driving over some deeper snow. While remaining in 2WD, I engaged the locker. Let off the brake, just a touch of throttle, and both tires did spin on the ice. Yet when I let off throttle, axle unlocked and then locked again, while tires were actually still in motion. Meaning that it would switch from locked, to unlocked, to locked again with tire(s) spinning at engine idle speed. Maximum tire speed generated during my test was about 10 MPH. Repeated three more times, and witnessed the exact same thing.

This seemed odd to me, since I am very familiar with differential locks (I own and operate a Kenworth with multiple differential locks), and generally when an axle is locked, it should remain locked. I also didn't like the fact that it appeared to be locking and unlocking while there was still tire spin. I would be in for expensive repair bills eventually if I attempted to lock my Kenworth's axles with any of the four ends in any type of spinout situation.

Opinions on this behavior?

 

Hey, what do you mean by unlocking when releasing the throttle? Were you hearing something, or just watching the LED on the ****? Not sure I followed you. If both tires spin when you accelerate, it's working as intended, no? When you release the throttle, it doesn't really matter what's happening, but tires should stop spinning almost immediately without power. Also remember the axle unlocks automatically above a very low speed (forgot the number), so you were probably exceeding it, and axle relocked when it fell below it. Let's see what other experts say. I haven't tried mine at all, so don't even know if it works .

 

I was watching tires switch from locked to unlocked, as well as being able to hear/feel the differential locking/unlocking on its own.

You mentioned a low speed cutoff? I was aware of a higher speed cutout, but not a low speed one! If that does in fact exist, I suppose that could explain it! Now why the system would cut out at a low speed makes no sense to me though...

I still don't like the idea of the ECM deciding to lock and unlock a differential that is in motion. If I hired a driver for my Kenworth, I would fire him instantly if I ever caught him locking the diffs with any tire slipping.

 

The only other thing I can think of, was the E-Locker wasn't actually engaging at all, and perhaps the traction control itself was simply just doing a quick brake on the one spinning axle...

Will have to do further testing.

 

I guess one other explanation could be that the locker will disengage under deceleration? That could explain it also. Decelerating from 10 MPH to idle engine speed tire spin on the ice, seemed to do it. Once tire spin was steady closer to idle speeds, it locked again.

 

The E-Locker automatically disengages when you hit 20 MPH. When you were spinning, the wheels probably achieved that speed and cause the locker to disengage, then reengage when your wheel speed dropped.

 

I didn't think I let wheel speed get to 20 in my test, but cannot confirm with 100% fact that I didn't either!

That could be what happened also... just reached the cutoff, it unlocked, and then locked again once under that speed.

I'm not sure how the E-Locker actually locks a 9.75" diff (which is what I have), but wouldn't the ECM locking/unlocking the differential while it is still in a one wheel spin mode, albeit slowly but nonetheless, create issues with stress on pins or whatever else it uses to lock out?

 

On my Kenworth, I have three lock switches. One is for the inter-axle, and the other two are for the 'front & back' diffs. These switches solidly control what is happening, with no BS.

They are locked, or they are not.

I'm just trying to figure out how this E-Locker works on my new F150...

 

I'll film it...

A "Locked" axle clunking and banging on ice!

 

Did you have traction control on or off?