Ok I need a little help here. I'm trying to locate the car I got my Posi/Disk Borg-Warner Rear Axle (9 Bolt Rear Cover) out of. I looked up info & there's suppose to be a tag glued onto the rear cover to give me the build date, Manufacturer (In this case Borg-Warner), ratio & differental type, now I found out the tag is long gone, but I do have the ratio tag's info & the limited slip tag. I'll list what I know about my Borg-Warner Axle....

The limited slip tag reads......
A ratio of 3.27
Part No. 10032270
Serial No. 12292

Now I also looked at the Third Generation (1982-1992) Tech Data Page & narrowed down the options to only the cars equiped with the B/W 3.27 Ratio Cars & found the following cars that had the option.
-86 350 TPI IROC-Z (Only 50 Built)-Highly unlikely it came from that car.
-87 350 TPI IROC-Z
Formula
Trans-Am
GTA
-88 350 TPI IROC-Z (Optional)
Formula (Optional)
Trans-Am (Optional)
GTA (Optional)

-89 350 TPI IROC-Z (Optional)
Formula (Optional)
Trans-Am (Optional)
GTA (Optional)

-89 V6 Turbo Trans Am-I think it wouldn't have come from this car as well.

I looked at the Ratio tag & got the ratio of the rear end, which again reads 3.27, so I had a hunch it was a Borg-Warner Unit, so rather then jumping the gun, I looked up the drivetrain options & that made me think more that it was a Borg-Warner & not just a standard Posi/Disk rear axle, but just to be sure I searched the boards here & got info that the Borg-Warner Units had 9 Bolt rear covers instead of the 10 Bolt normal rear covers. After counting the bolts on my rear end & the bolts on my 82' T/A's current rear end, I got the Deffinate Borg-Warner Unit.
Now other Borg-Warner Rear Axles had a 3.45 or 3.77 ratio available, so I didn't count those cars. I am pretty sure that the info I have provided is all I know about the Borg-Warner rear axle I have picked up for my 82 Trans-Am. Now my question is can anyone give me the Year, Make & Model of the car my rear axle originated from? I want to clean & rebuild the B/W rear axle before transplanting it into my 82 Trans-Am Project car, but am not sure if the parts from all the years of the Borg-Warner axles are the same or if they differ from year to year. I'd rather do this right then risk messing up the rear axle trying to use the wrong parts. Can anyone please help me? Thanks.

Joe

 

interesting.. i have the exact same axle, (p/n matches) and i am also in the process of trying to identify the contents/year/general info about this unit. no luck so far, but i think i will follow this thread.

-Camarogeddon

 

There's basically only two different styles of the Borg-Warner disc brake axle. The 85-88 version has the Saginaw cast iron calipers which are mounted with one side facing forward and the other side facing rearward (i.e. opposed mounting). Then there's the 89 style, which was the last year of the nine bolt, and it had the aluminum PBR calipers that are both mounted facing rearward. The only way you could narrow it down to the specific year, unless it's an 89, would be to find the 3 digit stamping code that's supposed to be on the front side of the passenger side axle tube. BTW, since your car is an 82, you probably have SAE brake lines. They changed all the brake lines to metric around 1984, so you might have to use an adapter fitting to hook up the rear line. Hope this helps you out some!

 

- the internal parts are interchangeable, except for the rare 2.77 ratio 9-bolts, which is a 2-series carrier, not a 3 like the rest. You just need to get parts for a 9-bolt, not a 10.

 

So I guess mine is 86-88 then, since my calipers mount on oposite sides & are a bit on the heavier side. I take it the parts for the 86-88 years are all the same then, & are they different for 89? Anyhow, this helps me out a lttle bit. Thanks Lots!

It's too bad the codes wasn't stamped into the housing like the rest of em' are. Great idea on the glued on tag on the housing cover. Makes it harder to locate the car it was removed from if the fricken tag gets damaged or falls on the interstate on the original car at 80 Mph & then gets transfered to an 83 T/A, & then I get it & have no idea how to know the year car I need to get parts for. Thank you Borg-Warner, GREAT IDEA there.

Joe

 

Internally, they're the same. The 89 just has different calipers.

Since it has cast calipers, it's not an 89. Since there are very few 86's, yours is either a 87 or 88. All the 9 bolt parts are interchangable except as mentioned above. The 2.77 ratio diff has a 2 series carrier. The 3.27 is the most common 9 bolt. There were a few 3.45 ratios available and the 3.70 was an option available from the GMPPC.