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It is what it is
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Discussion Starter #1
Ok, I have a problem guys. I blew out the spider gears in my truck over the weekend. My Dad got a set of spider gears from the stealer(gave them the last 8 of the VIN), but they wont fit, they are too big. What size is the rear end? I went on ringpinion.com and it shows both a 8.5 and 8.6 as a possible size for my truck. Also, when I called Summit, they said it was an 8.6 and didn't carry them. I noticed also that GM changed rear end sizes between the 2001-2002 builds and my truck is a 2002. WTF is going on? What size is it? I need to get my truck back on the road. The build date is 9/2001
 

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it is really 8.625 or somethin like that...but 8.5 would be correct, make sure you have the right part from the dealer and they didnt give you the wrong thing.
 

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Left Jizz
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1,225 Posts
on a suburban I would have thought it would be an 8.625. I would go back to the dealer and make sure you got the right parts. Also, Pick up a set for the 8.5 while you're there and see if they fit. If they do, take back the set of parts you didn't use.
 

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It is what it is
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Discussion Starter #5
Well, they did look up the parts by the VIN#, but when we compared the gears themselves you could tell there was a difference. Their seemed to be more of a "lip" on the gears from the dealer. The gears that go on the axles themselves were fine, but the ones that connect the 2 sides were too big. Wouldn't that point to the 8.5" instead of the 8.625"? ringpinion.com also shows that the same set of spider gears will work on both the 8.625 and 8.5 inch rear ends. Is that even possible?
 

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It is what it is
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Discussion Starter #6
Update: I went back to the dealer today, and they said the gears were packaged wrong. Apparently the gear that goes on the axle itself is smaller (but is he right number of splines, so it fits) and the gears that go in between them are too big, causing them not to fit. They have some on order now, should have them today. Apparently the spider gears for the 8.625" and the 8.5" rear ends are the same.
 
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