'14 F150 3.5 EB FX4
On my way home from work at about 35mph began hearing a grinding noise at first then like a binding and popping noise coming from my front left wheel/CV shaft area. Happened 3x and I was able to get it to stop by slowing right down to a stop and switching into 4x4. Only happens when I’m in 2x4, when those front wheels aren’t engaged, and (temporarily) stops when those wheels are engaged via 4x4. This seems to have happened after I dropped the transmission pan on sunday. changed filter, and only 5½ quarts of trans fluid. Seems like strange coincidence as the ****storm seems to be possibly coming from CV boot / transfer case which seems to me wouldn’t be affected by trans fluid complications. Or would it? I’m not super familiar with drivetrain issues (apart from switching out a bunch of CV axles over the years)
Questions, advice and insight is appreciated.
My guess is you have a busted CV shaft in the left front.
The reason it doesn’t make noise in 4x4 mode is everything is spinning at the same speed.
I’m not sure it’s the CV because when I switch from 4x4 to 2x4, by pulling the knob and isolating front wheels, (not simply 4x2 position where rear wheels are driving), there is no noise.
IWE’s (integrated wheel ends)- Ford’s auto locking hubs. Sounds like yours need replaced.
As I understand it, the hub is trying to lock when it starts the grinding racket. Hence, putting it in 4wd stops the noise because you’re locking the hubs. I’m not sure how they lock- through vacuum, or what. But, sounds like your issue.
on fords if you have a vacuum leak it will automatically put it into 4WD
I have an older (much older) Ford 4WD truck, w/manual-locking front hubs, and have heard that sort of sound when there’s a hub problem. In my truck’s case I have to disassemble the hub stuff, clean, and re-lube, that’s always solved the problem. That sort of thing would often begin with my making a mistake and forgetting to set the front hubs to freewheeling mode in 2WD, or visa-versa. Your truck’s configuration is different tho.