how can tell if i have limited slip or not. this much i know: 94' 5spd nvg4500 and dana 80 rear. i am trying to get the right gear oil and additive (if necesssary for light use)
thanks

 

If the tag is still attached to one of the cover bolts, you should be able to read the ratio on it, and there will be an LS in the middle if it is limited slip, e.g. 3.54 = "3 LS 54" on the tag.
If not, depending on how tight the LS unit is, you may be able to tell by jacking the rear up and, while the tranny is in gear, try to turn a wheel. If you can turn it, and the other goes the opposite direction, you have no LS or your LS is loose. I don't know that this is the greatest test, but I know with my very tight LS I cannot turn my wheels when the tranny is in park.
The sure way to tell is to pull the cover, and you'll see immediately what you have.
In most cases you'll use the same gear oil for LS or not, but add a friction modifier for the LS. You can buy everything you need and return the FM if it turns out you do not have the LS unit.


Chris

 

Stamey is right. the other way to tell is the build sheet under the hood. That will tell you if it was ordered from the factory with LS and look at the available oils. Valvoline makes oil with LS additive already in it. That is what I used. My brother used Redline. That had the additive in it too I think.

 

thanks. the tag was on the cover and no LS so i just went with 85W-90 gear oil and a paper gasket. so far so good.