I have an F250 4x4 with a sterling rear and was wondering how you can tell if its a locker? I am doing a frame up rebuild and will be rebuilding the front and rear axels (bearings & seals) and was wondering if it was a locker or not. If not, is it something I should look into upgrading during the rebuild? The truck will be a dayly driver with some off road use. First time doing this so any info would be helpful. I will be posting pics later as I go. Thanks

 

Ford Axle Code Chart .: Articles Compare your door sticker axle code with the codes in this chart (ignore where it says 1991).

 

Is there any other way. The doner truck I have for the drivetrain has been painted a few times and there is no longer a sticker

 

See if there is a tag on one of the rear diff cover bolts. Should have the same info if there is.

 

Nope, unfortunately everything is gone.

 

pull the cover and look inside. You need to pull that to rebuild it anyway. You can also spin one side by hand and watch which way the other side spins. If they spin the same direction you probobly have and trac lock diff, if the other side spins the opposite direction then you have an open diff.

 

Take the cover off the diff and take a pic and post it if you can't tell from looking... Do you know how an open diff looks?

Look for the clutches as you can see in this build thread...

Sterling 10.25 Trac lock rebuild

 

NO NEED TO PULL THE COVER!!!!!

Just jack BOTH back wheels up enough to clear the ground, then with it in gear (manual) or Park (auto) spin one wheel by hand, if it turns the opposite direction it is an open rear end.. If it won't turn it will be limited slip.

Then take it out of gear or park and see if it turns the same way as the one you are spinning. This will prove it is limited slip..

 

OK thanks, I'll check it tonight. If it doesn't have a locker is that something I should think about upgrading to??

 

There is a difference between a locker and limited slip differential. They both have advantages/disadvantages depending on your needs.

There is some info of how each type functions here: HowStuffWorks "Differentials"