I did the same.
I asked at my local dealer counter for it and they gave me a look like -
"Oh one of those perfectionist GX nerds huh?"
But then they told me that they fill T-cases from the same 75-90 drum as differentials...
So I ordered from a better dealership (Longo) and this is why I do my own maintenance.

 

Just finished changing the front & rear diffs on my 2017 @ 36k thanks to all the great info in this thread. I bought this GX CPO @ 27k, and I'm not sure what the previous owner used it for, but both the front and rear fluid was very dark. Looked more like used engine oil than the oil drained out in the GX Bob videos. The only thing I can add is the front skid plate was not nearly as heavy as I though it would be and was easy to remove and reinstall. Thanks everyone in here for the great info making this an easy job!

 

Has anyone else considered using Liqui Moly 75w MTF in the transfer case? This seems to be about the only/best option I can source locally (Napa) aside from the liquid gold from the Toyota dealer.

 

Interesting... I hadn't seen that 75W option from Liqui Moly. I usually hear about the Ravenol 75W.

 

To follow up, I emailed Liqui Moly asking about the fluid compatibility. Their response is below...looks like I'll be using the Toyota fluid.

Thank you very much for your inquiry and your interest about Liqui Moly Products.
Our Top Tec MTF 5100 75W is not the suitable product for this transfer case. Despite our extensive product range, we cannot currently offer any oil that meets this specification. In this case, we recommend using the manufacturer's oil.

 

That 5100 75w is GL-4, so if you want to use that product, you would have no issues.

 

Yeah honestly if the Ravenol 75w is OK to use that LiquiMoly 75w should be totally fine as well. As long as it is a MTG (manual trans gear oil) style 75w fluid, I don't think there will be any major issues with the AWD clutches or any synchro's or brass components (I think that is were GL5 oil is detrimental and will "eat" the brass).

I just did the driveline fluids in my GX - using Valvoline Synpower 75w90 in my Diffs and Ravenol 75w in the t-case. Changed at 80k miles and I would recommend the first change at 30k miles, and then at 100k miles. Fluid looked usable but for my preferences overdue for a change.

Honestly wish I saw that LiquiMoly had a 75w fluid, I would have gone with that and been the guinea pig

 

most diffs are broken in around 5000 miles. If you plan on keeping your GX for a long time, I would change at 5000 miles and then again at 15000 and then follow the normal or severe schedule as you feel fit.

There is way too much going on the both the front and rear to keep that fluid in for 30,000 miles

 

All myths busted on the transfer case and diff fluids after watching this video by Car Care Nut Channel.
Looks like the Toyota liquid gold TC 75W is an overkill and can do away with any 75W-90

 

I do watch and appreciate his content. I'm still comfortable using my golden fluid though :-)

It does have it's own unique additive package... I guess time will tell whether it was worth it or not.

https://bobistheoilguy.com/forums/th...5w-voa.269462/

 

There are a lot of these rigs out in the wild now with basically the same driveline for 11-12 years.
If what he says about Toyota/Lexus techs filling T-cases with 75-90 is true (and that is what my local Lexus service writer told me too), then he is probably right. This is a fuel economy thing.

Of course I just paid $80 for the unicorn semen in a can from Toyota when I did my 30K at home. Ah well, only $$$...

 

Hey all - I found a few threads that discussed this topic but didn't get an answer to my specific question. I have 92k miles on my 2014 and getting an oil change next week. The shop recommended changing the diff and transfer case fluids, which I do think it's time for, though I don't tow at all and rarely offroad. The shop recommended 80W-90 gear oil for both diffs and transfer case. After I read the vehicle manual, it says use 75w-85 for the diffs and 75w for the TC. The shop said they'll put in something different if I bring it in, but they only use the 80w-90. Any reason to not use theirs? Should I buy my own? I'm in central NC, so it gets cold, but not consistently below freezing for months on end. Thanks for any input.

 

I think you found your answer 'the shop said they will add whatever fluids I bring in'. I'd feel more comfortable having the shop add factory spec fluids and also better knowing they are adding exactly what I brought in instead of some bulk shop mystery fluid.

 

I changed my diffs and TC about a month ago and used Valvoline full synthetic 75W-90 flex fill packs for all three. I don't tow or off-road either. I at least wanted to stay with the same viscosity level that is in the owner's manual (75W).

 

That makes sense, thanks for the input.