Bonesoftitanium

The front differential is open (not a locker or posi) so it may only spin 1 front tire in 4x4 depending on traction. When on the lift and both tires are spinning try slowing one down, itll spin the other. Then try to stop both...good luck.

jp360cj

Nothing in the transfer can cause only 1 front tire to engage, it only engages the front driveshaft. I doubt the switch can cause it either. that would require each IWE to be independently wired to the switch. If you pull the vacuum lines off the IWEs, that removes the switch from the equation (as far as the IWEs engaging). If you get the same results, then the switch isn't an issue.

Honestly, it sounds to me like the open front diff is operating as designed. If you had a way to apply pressure to the RF wheel (such as engaging brake only on that wheel) or get pressure off of the LF (like flexing the truck where the LF gets lighter) then I bet you'd get the opposite result (LF spinning, RF not)

03f15012

The main two concerns I have are this concerning the situation. We just sold a 2013 w/ESOF, and both engaged and grabbed normally.

This one, being a year older isn't, plus the check 4x4 light is on. There's only certain number of components in the system, and when we have such a comparable test vehicle that works as it should...

I can't help but think they're comparable. Especially at this point when knowing the IWE's are fine, a lack of any grinding or whirring noise, but the LF wheel just isn't pulling at all. Except in that one small instance.

With the switch on how it's designed makes it even more confusing. I'm not denying your fact about the switch at all, but we're almost at a loss here.

techrep

iTrader: (1)

pull the vacuum lines and vent lines off the LF IWE...this will let you know if the wheel end is defaulting to the engaged position... then try your grass test. Or you can troubleshoot using a vacuum pump at the wheel end. The SOTF switch does not send a signal to each IWE..

jp360cj

Not exactly sure what you're saying here.


Have you tried to pull any DTC codes for the check 4x4 light? Has the broken switch been replaced? I don't know if that would throw the light, but if it needs replacing anyway, I would go ahead and do that. Typically, the truck's computer will motor tire spin and uses the brakes on tires that are slipping, acting like a limited slip. I wonder if this feature isn't working because of the check 4x4 light?

03f15012

Was referencing that the switch simultaneously activates the IWE's, not individually.

Regardless, had a friend bring by his '13. Swapped the switches, and no more check 4x4. After testing something out, the problem was is that out broken switch doesn't allow the locker to engage, causing the fault code.