Generation 5 Runner transfer case fluid.

[supton]

I put in Mobil 1 75W90 into my diffs and transfer case in very late 2015, I think. I *think* around that time it would be slow to engage 4WD--my typical method is to engage after I've gotten stuck. Anyhow, for the last few years it has almost always needed to roll a foot to click in.

This winter, including today's 0F high temp, it's decided to go right into 4WD without any sort of balking.

I barely drive the truck these days, and that Mobil oil must have 40k on it by now (I commuted in the truck in the 2015-2016 timeframe, then got my Camry for commuting).

 

[Astro14]

Originally Posted by supton
I put in Mobil 1 75W90 into my diffs and transfer case in very late 2015, I think. I *think* around that time it would be slow to engage 4WD--my typical method is to engage after I've gotten stuck. Anyhow, for the last few years it has almost always needed to roll a foot to click in.

This winter, including today's 0F high temp, it's decided to go right into 4WD without any sort of balking.

I barely drive the truck these days, and that Mobil oil must have 40k on it by now (I commuted in the truck in the 2015-2016 timeframe, then got my Camry for commuting).


You've used Mobil 1 75W90 in a transfer case that calls for 75W90. I would expect it to shift properly.

The issue here is that newer Tundras and Tacomas have a different transfer case, designed by Borg Warner. It calls for a 75W fluid. This is a low viscosity gear oil. Much lower than a 75W90 like yours.

So, the question is for the OP in his newer truck - with the new specification.

How does it work?

Mine works great in single digit temperatures. But then, I used the Ravenol 75W, which is synthetic and meets specification.

And it's that specification (75W - Low Viscosity compared with 75W90 or 75W85) that is causing all the questions.

They still call for 75W90 in the rear differential, and 75W85 in the front. AMSOIL says to use 75W90 in both.

 

[4WD]

Have owned many 4WD's nonstop since 1979 … never subscribed to engage after stuck
(I tend not to get stuck) … and have never seen an owners manual suggest that …