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Rear Diff oil type.


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  #1  
Old  July 20th, 2009, 10:09 PM
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Rear Diff oil type.

I'm planning on changing the rear diff. lube on my 2000 Silverado, and my 2005 Suburban. Both have 4 wheel drive. According to the owners manual it recommends synthectic 75W-90 oil. I went to a local parts store and they did not have 75W-90. They had 75W-140, and 80W-90. I was told by the owner of the store that the Amsoil 80W-90 will work just fine. Just wanted to get some other opinions. The oil does meet the GM requirements. Thanks.

  #2  
Old  July 20th, 2009, 10:14 PM
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I used 80 90 but is it a possi unit? If it is you need the GM possi additive or you will get possi clutch chatter.

  #3  
Old  July 20th, 2009, 10:23 PM
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I don't know. How do I find out? The label on the back of the qt says it complies fith GL-5 and GM specs.

  #4  
Old  July 20th, 2009, 10:36 PM
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I think if you look at your RPo codes in your glovebox there should be a G80 Which is possi and you will need the GM additive!

  #5  
Old  July 21st, 2009, 6:50 AM
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Jack the back of the truck up so the back wheels are off the ground. Put it in neutral spin a back wheel by hand, if the wheels go the same direction put the addative in. If one wheel goes foward and one goes backwards you do not need it.

  #6  
Old  July 21st, 2009, 9:51 PM
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I thought the G80 was an Eaton locking diff, not a clutch type. But I don't know when they started using it.


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