Correct front axle fluid?

[dross99_si]

2007 Tahoe LT 4WD
Should I be using 80W-90 or 75W-90 synthetic axle lubricant in the front differential?
When I scour the web I'm finding conflicting information..
Thanks guys!

 

[swathdiver]

2007 Tahoe LT 4WD
Should I be using 80W-90 or 75W-90 synthetic axle lubricant in the front differential?
When I scour the web I'm finding conflicting information..
Thanks guys!

80W90 for the front Andy. 75W90 synthetic for the rear. I had trouble locating GM fluid so I went with 2 bottles of Lucas 10043 and my front axle quieted down some. I bought a good drill pump that you can borrow if you like. @iamdub or someone used Supertech from Walmart and says it was good too.

 

[dross99_si]

80W90 for the front Andy. 75W90 synthetic for the rear. I had trouble locating GM fluid so I went with 2 bottles of Lucas 10043 and my front axle quieted down some. I bought a good drill pump that you can borrow if you like. @iamdub or someone used Supertech from Walmart and says it was good too.

Thanks James. I figured I'd ask on here for the heck of it. Called parts dept at Chevy and they told me 75w-90 synthetic for front & rear diff.
I already purchased the 75w-90 darn it. Should I go return it or is it safe to use?

 

[swathdiver]

Thanks James. I figured I'd ask on here for the heck of it. Called parts dept at Chevy and they told me 75w-90 synthetic for front & rear diff.
I already purchased the 75w-90 darn it. Should I go return it or is it safe to use?

I've read on here that lots of guys use the same rear fluid for the front. I do not understand why GM specified synthetic for the rear and not the front and 5W thicker oil for when it is cooler. Can't imagine that it makes much difference in the long run.