Impact wrench in the lugs or impact driver? You said wrench for building the rack. My impact wrench blows off the lugs on my 14 F150 after I manually torque them to 150. Not sure if you were using an extension or something but mine has been flawless.
Dtuck, I was using the impact WRENCH on the lugs. Like I said, I thought they might've been too tight the first try so i re-torqued them to spec (140 ft-lbs) and tried again. No dice. I was using a 22mm impact socket mated directly to the tool, no extensions. I tried with different batteries, including the fully charged brand-new 4.0Ah, to weed out other possible variables and it only got worse with lower amp batteries. Could've just been a dud tool, who knows.















