Differentials and Transfer Case Fluid Change

My 2008 Tundra is a 4.7L and 4x4. I currently have 135k miles on it and to my knowledge, the fluids have never been changed. The Toyota dealer is the only one that has serviced my truck, and just mentioned that I may want to put those services on my radar of things to look at doing. I'm looking into it and naturally they want me to use the oil from them that is $40 per quart.

According to my owners manual, it says the transfer case takes about 1 quart of

$39 75W-90 GL-5 Limited Slip, Ultra Long Drain 500k Miles, Manual Transmission, Gear/Differential Lubricant (1 Gallon)

75W-90, GL-4 or GL-5. The front differential takes about 2.2 quarts and rear is almost 5 quarts, both of 75W-85 GL-5. I tried researching and I feel pretty comfortable doing the rear change, but haven't looked much at the front or the transfer case. My question is, which oil should I use? I have seen Redline and Mobil 1 both come recommended on here.

 

Interested in responses as well.

 

I used the Mobil 1 w the additive for the diffs.

 

I ran Mobil 1 75w90 in both front and rear diffs. doesn't matter if has LS or not as the diffs are both open. The transfer case I ran Ravenol straight 75w I got on Amazon. Nifty bottle made fill up easy and from what I read is the same as the Toyota fluid.

 

So looking at a lot of the auto parts stores online, it looks like 75w-85 is not that common?? Almost everything I'm seeing is

$39 75w-90 GL-5 Limited Slip, Ultra Long Drain 500k Miles, Manual Transmission, Gear/Differential Lubricant (1 Gallon)

75w-90. Can that be used instead? I see 75w-85 is made, but might have to order that separately.

 

Correct. 75w-85 is not that common. I fair amount of people say they just use

$39 75w-90 GL-5 Limited Slip, Ultra Long Drain 500k Miles, Manual Transmission, Gear/Differential Lubricant (1 Gallon)

75w-90. I use Redline 75w-85. You can find several sellers online. Not exactly cheap, but it's cheaper that Toyota 75w-85.

 

Yea, Toyota oil was going to be about $250 for just the material, before any labor. I imagine they would probably tell me it's a 4-5 hour job as well.