Front Diff Fluid Question

[Mossyoakglock]

Search is not working here at work, so I'll ask. I'm going to change the front and rear diff fluids in an 07 Avalanche and 08 Silverado, both with the G80. With the rear, I'm using the recommended 75W-90 Synthetic from Mobil1 and I know not to add any LS additive. But, with the front, it recommends 80W-90. I can't find the post, but I know I've read it somewhere, but is it safe to use Mobil1 75w-90 in the front as well or should I just stick with regular 80W-90? Do I need to add any additive in the front diff? The manual recommends 80W-90.

[Matt_]

Stick with 80w-90 non synthetic fluid for the front. It also does not need any additive.

[Spurshot]

In the Helms/GM manual there is a lube spec. Just use a lube that meets or exceed that spec. I'm not near my manuals now, nor do I have one for my later model 08 truck anyway. But, Rich should be able to provide the spec. I recall finding the front lube meeting the spec at a local Kragen. It was a Valvoline brand. It's been 8-9 months ago. sorry.

[Beebe]

In the Helms/GM manual there is a lube spec. Just use a lube that meets or exceed that spec. I'm not near my manuals now, nor do I have one for my later model 08 truck anyway. But, Rich should be able to provide the spec. I recall finding the front lube meeting the spec at a local Kragen. It was a Valvoline brand. It's been 8-9 months ago. sorry.

 

+1 for Valvoline. I just did both front diffs on my 00 Silverado, and 05 Suburban. I used the Valvoline 80W-90, and it does not need the additive.