how do i find what rear axle i have?

[AWCougar]

Normally this would be easy open glove box and see the pretty stickers. which would give you the RPO codes to look up. one problem.
this used to be mom`s daily driver and well she broke the glove box and had the glove box replaced. Can i use the vin to find out which rear axle i have, the gearing, etc. or were they straight across the board with the 8" rear ends and 3.42's? I have also looked at the rear axle itself and didn`t know exactly what i was looking for. any help would be awesome.

[djthumper]

If someone has access to the GM system they can actually look up the RPOs with the VIN.

[AWCougar]

... to the dealer

[djthumper]

Do a search here and on GMTN for threads of people that may be able to look it up.

[DirtyBacon04]

at least one of our members here has access to the GM database, forgot the username. He looked up the VINs for me on my salvaged axles.

[jonbo2002]

oh oh oh that me lol just give me your VIN and I'll get the ratio for you

[djthumper]

LOL, we have had a few... I thought one was you Jon but I am just so tired.

[jonbo2002]

I'm our resident salvage guy

[mikekey]

Nwere they straight across the board with the 8" rear ends and 3.42's? I have also looked at the rear axle itself and didn`t know exactly what i was looking for. any help would be awesome.

Jon (the member posting above me) is the one who works for LQK or LKQ or whatever that yard is called. He can verify axles, he's helped me a few times.

To answer your question, EXT's, XL, XUV, 9-7X and the 5.3L version of the SWB GMT360 came with the 8.6" rear axle. The Trailblazer SS featured a 9.5" rear axle. All are direct bolt ups for the standard 8.0" rear axle featured in all SWB models. There are TWO versions of the 8.6", as they changed the ABS sensor position in 2006. Being a 2003 model year you can use a rear axle from any EXT/V8. 06 and up can only use 06 and up if they want to keep ABS.

RPO Codes for gear ratios:

GU6 = 3.42
GT4 = 3.73
GT5 = 4.10

[navigator]

.....To answer your question, EXT's, XL, XUV, 9-7X and the 5.3L version of the SWB GMT360 came with the 8.6" rear axle. The Trailblazer SS featured a 9.5" rear axle. All are direct bolt ups for the standard 8.0" rear axle featured in all SWB models.....

Just to clarify the 9.5 should bolt right up but the driveshaft I think needs to be shortened.

[AWCougar]

that answered a lot more than my question. which leads me to believe that i have the 8"
and i`m going to shoot jon a pm

[jonbo2002]

nice you got a 3.73 and G80 but you're not going to have the 8.6 in a short wheel base and I6 on an 03

[AWCougar]

I'm going to go write that in my glovebox with a sharpie

[The Roadie]

Just memorize them. We can all memorize G80; just 3 more codes.

[navigator]

I could never keep them straight. I knew you had some prefix and then 4,5,6.
I can remember them like this
GU6 = 3.42 GU needs to Grow Up
GT4 = 3.73
GT5 = 4.10
Then I remember $5 is better than $4.

It is stupid, I know but it works.

[DirtyBacon04]

I used to say "if it's stupid but it works... it aint stupid"

thanks for proving that wrong...

[dvanbramer88]

Burn.

[Moots1288]

Hmmm, that had to hurt.