I recently purchased a rearend from a salvage yard for a Hotrod I am building. The guy at the yard said it came from a 1997 Blazer. It has disc brakes and a 3:42 ratio. The Blazer has long ago been crushed so there is no way I can check the RPO. The guy at the parts store said GM didn't start putting disc brakes on Blazers until 1998. I need to know how I can tell if it is an open, limited slip, etc. Thanks

 

Take the diff cover off. If you can see the spider gears then it's an open. It you can't see them, then it's probably the LSD. If your still not sure, snap a pic and post it, and I or someone else will be able to tell you.

 

98 was the first year for disc brakes on the rear axle.

As far as telling what gears are in it or open vs. G80 gov-loc (no LSD's), open it up as stated.

 

The original rearend I used was an open [I can see the spider gears]. The one I am in the process of installing must be a limited slip. There are small cylinders and springs in the opening next to the ring gear. Sorry, I can't figure out how to post pictures. I will keep trying.

 

If it looked like the picture below, it is a G80 rear end:


But lets get the terminology correct here. The G80 is not a limited slip rear end. It is called a gov-lock which has the ability to act as an open differential for turning and higher speeds, but can lock up when the wheel speed difference side to side exceeds ~200RPM under a set differential main case speed (related to ground speed).

 

My mistake, but LSD is just a broad term. Don't want to mis-inform anyone though.

 

My rearend looks exactly like to one in the picture. I have aG80. Thanks