What rear end do i have?

1G2FS21H6HL234792

 

2 wheels

drive shaft

torque arm

2 LCAs


How many bolts does it have? I'll give you a quick clue: if there's 9, it's a 9-bolt. If there's 10, it's a ..... well, I'll let you do the math.

 

We don't have nearly enough information to tell. As said above the first step is determining 9 bolt or 10 bolt. Even then there is no telling what gear set is inside or whether or not it should be a posi. If you're crafty you can count the number of turns of driveshaft vs turns of the axle to determine gear ratio, but it may be easier to just pop the cover and take a look. Count the number of teeth of big gear, count teeth on smaller gear. Big number devided by small number.

You're gonna have to get a little dirty anyway.

 

10 bolt 2.73s would be my guess

 

Well the reason im asking is because i heard from a family friend who was a GM master mechanic for like 30-40 years that i have a posi-trac with possibly 3.23's, but i thought i would ask around first. And yea its a 10.

 

With the LG4 and the manual you would of gotten 3.23s, however from your profile you say it is an AT, which means 2.73s. Posi was not standard, you could either have posi or not, depending on your options (I believe the RPO code is G80).

 

If you're lucky there will be a metal tag on one of the differential cover bolts with the ratio stamped on it. (My GTA axle has one).

Is your service parts ID (SPID) sticker still on the car? They are usually found in the center armrest hatch, or in the locking hatch in the rear compartment. It will have the RPO codes of the options the car came with. As AmorgetRS says.. G80 is posi.. There should be another code starting with 'G'. That will tell you the ratio.

 

On the 10 bolts axle assembly the ratio code build plant and build date were generally stamped in the right axle tube.Look on the front(pinion side)of the passenger side tube.You may have to use a wire brush and it may or may not be readable.As GTA Jim pointed out the axle codes will be on the SPID decal(make sure the VIN on it matches your car's VIN.
But the only certain way to determine what you have is to remove the diff cover.Over time changes could have been made.
GTA Jim does your GTA have a 9 or 10 bolt axle?The reason I ask is for the most part on 10 bolts the metal tag you speak of just denoted limited slip(for fluid purpose).

 

moo