I noticed the other day that my truck has a front locking differential. Do these trucks come like that from the factory or did the previous owner install one?

 

They do not come OE with a front locker, and until 09 did not come with a rear locker. The front is pretty much useless/problematic except in offroad or very slippery conditions. Also when locked it will have a tendency to go straight even with the wheel turned.
Stock front axle is a 8.8 reverse cut OPEN diff.

 

How did you "notice" the front was a locker???

 

Chained it to a tree a proceeded to dig 4 holes in the dry ground. I don't see any other possible cause than a front and rear locker. Did they not put rear lockers in pre-09 FX4s?

 

No rear lockers prior to 09, just LS or open.

 

That doesn't mean you have a locker in the front. My 1977 did the same thing last year when I was pulling a stump in 4wLo and I guarantee it does not have a front locker, and the rear LS is 102,000 miles and 33 years old.


Just meant that the two front tires had near about the same traction.

Try it again but first, soak the ground under one side.

I remember back in the '70s when full time 4wd became available, fellow had a Dodge pu and it w near new, full time, no LS and I won a small bet with him showing him it will spin just one front wheel and not move. Left it in full time and pulled one wheel on ice next to big snow bak, try to push snow some, and that LF wheel on ice spun, no rear wheels spun at all. All power wa going to the wheel with least traction as there was no lockers or LS anywhere.