for the longest time i thought i had an open rear end where only 1 wheel spun, but saterday me and my dad did some work to my 86 and got it running smoother and he decided to do alittle burnout in my garage lol. well i noticed that the passenger rear started to spin but shortly after i saw the drive side kick in and start to haul *** like the passenger. so im confused!!! do i have a limited slip rear end or an open?!?! or are they the same thing??

 

The usual test is jack up the rear and turn one of the back wheels. If the other wheel turns in the opposite direction it's open and if it turns in the same direction it's limited slip.

 

However, a govlock type diff can only be determined by removing the cover and looking inside. Driving along it will act like an open diff but if one wheel starts to spin, it will lock up to provide power to both wheels. Jacking up one wheel and spinning it will act just like an open diff.

Govlock diffs are not very strong. They're good for general street use but the locking teeth are not strong enough for performance use.

 

If you can keep both wheels spinning evenly at the same time then it's limited slip.

 

The only accurate test is to lay off all the "turn the wheel" BS, and instead, just decide to catch up on the long-overdue maintenanace you've been putting off putting off until sometime in the future, and change the fluid, as it needs DESPERATELY since you haven't done it lately; and LOOK AT THE PARTS while you have the cover off.

All else is just a guess.

If you don't know what you're looking at, take a pic of what's inside the "window" of the carrier, and we'll be able to tell you in excruciating detail what it is.

 

I just did an oil change last year about this time on the diff, when the wheels are off the grond the wheels spin opposite of each other but like I said they both start spinning like a mad house after my passenger starts to slip

 

There are conditions where an open will 'appear' to be a limited. As Sofa suggests, to be certain drop the cover. There are pics of the various L/S versions in the 10-Bolt FAQ.

JamesC