K Dog

I have a 05 f150. My rear end is slipping in 4 high when in snow and mud. I was told change the oil. I cant remember what kind I should use. Anyone know what to use?

tiresmoke

When you put it in 4wd, are your front hubs locking in? Spinning the rear wheels would indicate they are not. IWE actuator could be the culprit here. Doesn't sound like a trans problem, but possibly something in the transfer case.