I noticed during a snow storm last night that when I was in 4 hi, if I either was turning or backing up, my truck acted like the emergency brake was on, felt like it was in the front end, it is a 2004 FX-4 Any ideas or is this normal ?

 

THat's normal. Even though it was snowing, was the road slippery? If the one wheel can't slip relative to the other wheel, you will get some binding. Not an issue as long as you don't do it all the time.

 

What is doing it, the posi in the rear ? It was a little slick out, I've had trucks in the past with posi in the rear and never had one act like this !

 

I had the same problem. Took if off-road in the dirt and everything works fine.

 

Twinsdad98 is right. The cause is in the front end, not the rear. It is really noticeable on dry pavement which is discouraged due to that binding. If it goes away when you straigten out, that most likely is the cause.

 

It doesn't do it on dry pavement, or in 2 wheel drive, what would be doing it ?