To the O/p.
On a side note Royal Purple needs no extra additive.
Al.

 

I lied to dog a little. I did have the cover back on and had started filling it back up. But, I actually ended up not adding any additive. As I was getting close to the top, I decided to put the plug back in and go bend on it a little bit and see if anything seemed to be binding up - but it seemed fine. So I topped it off with RP and no additive. So, I get to take back a whole bottle of 75w-90 I didn't use on the front end and the LS additive I bought. Looks like I can afford to eat dinner now.

 

Go run you some tight circles and if it doesn't bind then either you don't have LSD or the amount in the RP was enough...

 

Yeh, did that based on your suggestion earlier Hammer. All seems well. Thanks for everyone's help. I think I've got all the work done I wanted to get done now. And now it's about time to do the plugs again. Always something right?

 

Well, LSD or no. Clips or no. The bearing caps look good, so nothing has been chewing into them. I think in an earlier post you said your gear oil came out clear of shavings, too. Not anything conclusive, but good news so far.

At the risk of beating that poor horse further into the ground... from the list you just posted just a bit ago, the line -after- your last line is where on my sheet "Anti-Spin" is listed.

 

Jack up the rear end so both rear wheels are slightly off the ground. put the truck in neutral. spin one wheel forward with your hand. If the opposite wheel is rotating the same direction(Forward), you have an LSD. If the opposite wheel is spinning in the opposite direction(backwards), you have an open diff.

 

That wouldn't have been me. I just drained it for the first time this morning. The fluid looked good and everything inside is visibly good as well. There were some shavings collected up on the magnet at the bottom but I suspect that is normal for 90k miles.

The front end fluid was a bit darker. Looked more like used oil coming out of the pan than the rear fluid did. Filled that hole up with Royal Purple as well.

 

I don't see any evidence to think you have the factory LSD. Nothing on the window sticker, nothing on the build sheet, nothing in your pic (although it is at a tough angle) and by 90k you'd have at least found broken "c-clip" fragments when you pulled the cover.
As for handling in the snow, often an open differential will perform just as well if not better in snow than a LSD or locker.

To be honest, even though I have a far superior to stock Auburn LSD in the rear, even off-road it's hard to tell. Now if I gun the gas in a semi-slippery situation, I'll feel the LSD grab. The Vari-Loks in my Jeep (both axles) is pretty easy to tell. If I'm coming around a turn on a wet, slick Georgia red clay road I can feel them kick in just as the rear end starts to break loose and actually pull the vehicle back on line...

 

I agree. Your sticker needs to say anit-spin diff

Here's what my sticker reads;

Optional Equipment
Anti-Spin Differential Rear Axle........$325

You no have LSD...haha

 

Looks open to me, limited slip carriers are usually more squarish.