hey guys i have a 2007 fx4 lvl 2 , it was icy one morning so I decided to keep it in 4wd hi [first time using the 4wd on the road above 80 kmh on the road] and noticed that there was this bump like feeling in the front end of the truck and it does it only once in a while [no matter what speed or if I'm on the gas or not] the 4wd always works wonders and never "skips" so I cant see how it could be transfer case related as it was also rebuilt a year ago with the transmission. in 2wd It won't do it. i thought it could maybe be the front driveshaft u joints binding up and letting go but I'm not that much of a part-time 4wd guru. as i said the 4wd never disengages and engages randomly as it would of have done it when I was out playing in the snow. thank you for any leads clues or solutions if any of you guys ever had this problem or have more knowledge than me in this department. cheers.

 

Welcome to the forum.
If 1354 TransferCase has NOT been drained+refilled in last 33kMiles, best to do that.
If TC Fluid level is low or has internal damage or if ShiftMotor is weak, been known to "skip a beat" in 4WHi as you describe.
Open 1/2"*14npt UpperFillPlug first; note level of old fluid using finger as a dipstick; it should be just below FillBung.
Open 1/2"*14npt LowrDrainPlug, may be behind a CounterWeight; let that completely drain; note volume+color of drained fluid.
Replace LowrDrainPlug; smear of RTV on threads.
Refill with fresh MerconLV (not MerconV) fluid; roughly 1.5qts until it overflows from FillBung.
Replace UpperFillPlug; smear of RTV on threads.
Inspect 4x4ShiftMotor (back side of TC) for corrosion+damage, & the underside generally for leaks\damage, while your there.
This is a good time to also service Rear+Front Diffs with fresh 75w140+75w90 GearOil, if that has not been done recently.