rear axle swap
 

i was wondering if anyone has done a rear axle swap on a den 2 4 door blazer, looking to try and find one off an extreme s10 pickup. any comments?

I would love an answer to this one, I am sure that GM produced at least one axle version on a production car or truck that was a good limited slip for the S10. If it is the S10 "Extreme," I'm in! My salvage yard is just full of GM producrts :icon_chickendance: With an open Rear and a single drive shaft up front we cannot get 4WD. I would be a little happier with 3WD.

im pretty sure that i read somewhere that the extreme has the limited slip, dont quote me on it but i think i did.

so google helped me out on this... here is a link that showes what s10's have the 8.5 rear end-----
How to find S10 8.5" rear end - PerformanceTrucks.net Forums

Thanks alot DonL!

It sounds like you have already done the research on this.

I take it that the S10 Extreme is a direct swap with the 2nd Gen S10 Blazers and the gear ratio still matched the front diff. Are we on the same page?

I get most of my parts from a U-pull it salvage yard. When I finally stumbled onto a ZR2; I was expecting fancy striping or at least "ZR2" in big characters on the body (Like the "Z71 or "SS" for super sport). If it weren't for the spare tire carrier, I woulds have walked right past it. Is there any markings to show a salvaged truck is the "Extreme" S10?

DonL, if your truck is a 4wd model, be aware that the Xtreme's were only offered as a 2wd and the axle width is different than the 4wd models.

Here's the width breakdown:
2wd 54.5"
4wd 59"
ZR2 63"

And I assume that you are looking for a true LSD and not the G80 Gov-loc rear axle. If that is the case, I'm not sure that any of the s-series trucks were ever equipped with limited-slip/posi-trac diffs from the factory. The Gov-loc differential acts as a limited slip with preloaded clutches that will then fully lock up when it detects one wheel spinning faster than the other (unless you're going too fast).

G80 is the RPO code for the Gov-loc differential so that's what you'll want to find in the RPO code label located in the glovebox. The RPO code label will also have the gear ratio code which you'll need to match up with your current RPO code to keep the same ratio for speedo and shifting accuracy. This is even more important if your truck is a 4wd, if you wanted to use 4wd again anyway.

Thank you Swartlkk

If I understand you correctly; the G80 Gov-loc rear axle (standard on 4x4 S10 Blazers) already gives us both wheel traction in mud, sand and loose ground at off road speeds.

My glove box was spray painted so no RPO codes. I pushed the VIN through the GM database and only got recall history.

yes ive noticed that thank you... unfortunately for me, i do have a four wheel, and even more unfortunate, there are even less 4x4 with posi rear ends... i will be hunting for a while for the rear end im looking.

DARK1 - there was a site i went on that let me search my vin number and the specifics that came with it on first purchase, let me see if i can find it again, ill send you the link.

Compnine.com will run 5 VINs for $5. They used to be free, but sadly that is no more. You may be able to have the dealer print you out the RPO codes.

DonL, lets call it the G80 diff. Calling it a posi-trac is misleading and incorrect. And I wouldn't say that even less 4x4's came with the G80 rear diff. But Dark1, it definitely is not standard on all 4x4's .