I have a 94 s10 blazer 4x4 4.3 auto. The other day I was driving down the interstate going 70mph when I felt a big bang and lost all power. I made it off the road. At first I thought it was the tranny but when the tow truck driver called me back he said all 5 wheel studs on the driver side were sheared off.I havent had a chance to pull the rear diff off to see but with the drive shaft out the tranny shifts through all the gears with no problems. If it is the rearend and I find one on craigslist how will I know if it is the same gears?

 

 

The gear ratio will not be stamped on the axle housing itself. For that you have to look up the RPO codes (sticker in glove box) and go from there. Being a 1st gen, you likely have a 28-spline 7.625" GM rear axle.

Did the wheel fall off on the driver side? If all you did was sheer the wheel studs, you should be able to get that fixed up for under $30 (studs & new lug nuts). Wheel studs are fairly cheap.

 

Your RPO code for the rear axel will either begin with a "G--" or "H--" (more likely a G, mine is GU6 which is a 3.42 Ratio) If you give me your code ( G or H) I can tell you what ratio rear axel you have. If you find a Parts car you can compare the RPO numbers too see if they match.

 

So, I am going to replace my rear end with any other out of another truck that has the same RPO code in the glove box? I am going to go get my code now, I thought I just had to match the axle code. I am glad I ran into this thread.

Edit: My glove box has these 3 codes... GQ1, GT4, G80

So, how could mine have those 3 codes. look in the glovebox at the RPO codes.

GU2 2:73 ratio

GU4 3: 08 ratio

GU5 3:23 ratio

GU6 3:42 ratio

GT4 3:73 ratio ----This is my ratio

GT5 4:10 ratio

GQ1 Open Differential Rear Axle ---How could I have this code

G80 Positraction/Locking Rear Axle ---AND this code? I know I have posi cause they do lock. The wheel only spins a little when theyre off the ground and then they both spin.

 

I don't where your getting your info from but here's what mine says:

G80: Axle Positraction, Limited Slip
GT4: Axle Rear, 3.73 Ratio (Dup with 5x1)
GQ1: Axle, STD Ratio

 

Probably from an unrepitable source from Google. Thanks for the clairifycation. I now know what to search for during my next trip to U- Pull It.

Oh, and the whole reason why I'm changing out my rear is the inner pinion bearing is bad. It has been grinding during deceleration for a few years. I'm still a little shaky about opening something like that up considering the percision that it takes to get it back together.