Offroad Trailblazers and Envoys

Axle swap purchase; quick verification

G80, GU6, GT4, GT5, WTF? This section is for gearing and driveline stuff.

by med71 » Fri May 11, 2018 5:34 pm

I just picked up a rear axle from a 2003 Trailblazer EXT GT4 G80. Based on what I read, I believe this is the 8.6 3.73 LSD axle. Please let me know if I'm wrong or anything else I may need to know when I put this in my 2003 Envoy.
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by DirtyBacon04 » Sat May 12, 2018 5:08 pm

Correct.
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by med71 » Sat May 12, 2018 10:27 pm

DirtyBacon04 wrote:Correct.


Awesome, thanks...now to get the spacers, shocks, and springs to get this thing started.
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by med71 » Fri May 18, 2018 6:13 pm

I received the axle today; I'm going through it to make sure I got what I ordered. Since I just discovered that the trailblazer 8.6 has the same diff cover as the 8.0, I couldn't tell with a quick visual inspection; I was expecting the typical round one...sigh. The only stampings I found were H330028565 on the cover and 40008140; I read somewhere that 8.6 may be stamped on it. Any ideas?
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by AzEric » Mon Jan 14, 2019 10:56 pm

Mark,

I know this thread is 7months old, but I am in a similar situation to you. I believe I ordered the correct axle for my swap, but I am not sure upon receipt.

Did you ever find a way to tell, unequivocally, that you have the 8.6 and not the 8.0???

Thanks!

Eric
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by Wahugg » Tue Jan 15, 2019 5:13 pm

Eric,

Take a half shaft out and count the splines. 28 = 8.0" diff and 30 spines = 8.6" diff. Also see my response in your other thread.

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by AzEric » Tue Jan 15, 2019 11:53 pm

That's deeper than I would dig if I were looking thru a pick-n-pull, and further than I would want to disassemble if I were going to then need to send back or resell. I've got fat fingers, those c-clips are a pain to get in/out for me. :twisted: But, it would definitely be the end-all answer I was looking for, Thanks!

The stamp on the cover is definitely more user friendly, although it is VERY faint, all it took me was some sandpaper and air (or brake parts cleaner) to be able to see it.

:cheers:

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by DirtyBacon04 » Fri Jan 18, 2019 11:28 pm

There's a couple members here with access to the VIN database. If you can provided the VIN for the vehicle it came from, they can check to see what that vehicle was originally equipped with.
If it was an EXT or V8, then it came with the 8.6.
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