Front differential vent fitting

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MIHELA

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It's the same axle. If you replace the vent fitting, you can run 75w90 without worry and in cold places like here in South Dakota, you WILL notice.
 

alpinecrick

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The TSB mentions that 9.25 diffs and extreme cold with 80W90 can cause failure due to lack of lubrication. 2004+ vehicles all came with the white vent and 75W90 from the factory.

The local GM service manager told me the same thing about 75-90 gear oil, although he didn't mention anything about a different fitting....... My "one way valve" is still intact on the vent tube on my trucks and I speculate that would help keep it from siphoning.
I have been running 75-90 for years in my diffs.
 
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east302

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The white vent was too big, but just barely. Couldn’t get it to work. I have no idea what vehicle this differential came from, but it’s getting old fast.
 
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