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Discussion Starter · #1 ·
2005 sierra sle crew cab 2wd. RPO code in the glove box states the truck is equipped with a G80 rear differential. Today I jacked the rear end up and spun one tire forward and watched the opposite tire spin backwards. How in the heck does that work? I placed this thread in lifted suspension due to the fact the truck has 10"s of lift and I'd like both wheels to drive the rear. Do I need to replace the whole diff or just buy a $1000 conversion kit? I have no use for 4wd where I live.
 

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'14 Chevy Silverado Owner
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229 Posts
It's an auto locking diff. So it's normally limited slip and when it feels slipping then it locks in posi. My 98 had the G80 and it did the same thing, one turned one way and the other turned the other direction. I know it was the G80 also because when I used to do burnouts it would either be in posi or start with one and then lock into posi and then both would spin.
 

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Multiple GMFS owner
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2,098 Posts
Congrats it's working like normal, pull the cover and see what you really have if you are worried about it.
 

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G80 is an open dif until it senses one tire spinning faster. Jack your truck up and spin one back tire as fast as you can, most of the time you can spin it fast enough to get it to lock. It will jolt and suddenly stop spinning, and then will be open again.
 

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Discussion Starter · #8 ·
It has 3.23's in the rear and I like throw in 4.56's. Is there a cheaper place to get a new ring and pinion besides summitracing?
 
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