Diff lube interval?

So my truck is just over 50K and I’m getting ready to change diff/transfer case lube. I’ve always had AWD vehicles and changed front and rear at the same time.
Since my front diff is only engaged a small percentage of the time, do I go for a longer interval? Using Mobile 1 synth all around.

 

I would not go much over 50k
Some guys do it every 30k.

I try to stick with all 3 every 50k
But the transfer case doesn’t get used as much as the others, so in theory it takes the least abuse. The spider gears are always turning in the front diff. So it sees more action than you think.

 

In addition to this, I like to remove the fill plug and stick a finger in the front diff. See what the fluid looks like. If it's still clean and clear, you can go a little longer. It's also a good check to verify your level is good.

 

Every time I've done the rear diff, it was dirty and well used. That one is every 30k

Every time I drained the front it was clean, but I've still replaced it a few times

So yes you can stretch out the front interval.. but don't forget about it