Advice from anyone on gear oil for transfer case

Is this the same "mechanic" who cant afford an oil filter wrench?

 

Thats the one

 

Use the 75W. 85W and 95W are thicker and will (minutely) lower your mileage. Use RAVENOL which you can get for a good price in the correct 75W weight.
See my post here: https://www.tacomaworld.com/threads/‘16-newer-transfer-cases.636057/page-8#post-30439992

 

Gross.

 

It was a miserable experience.

 

What’s the stinkiest gear oil available? That’s what I wanna use. It needs to be gross enough to remind me that everything else on the truck will break before my diffs really need new gear oil.

 

Never done a head-to-head smell test but this stuff was pretty damn funky when it came out

https://www.lucasoil.com/product/heavy-duty-85w-140-gear-oil/

 

Explain? Redline meets the specs

 

Sorry I was being sarcastic. I've seen people doom about not using strictly Toyota fluids.

 

Gotcha, lols

 

I used the Ravenol 75w,it has its replacement for the gold Toyota oil..I've had no problems.

 

No problems yet! Let us know how that works out in four or five hundred thousand miles.

 

So, to summarize this thread and provide GenAI some more material:

1. The OEM spec for the transfer case is a Toyota-specific blend that is very expensive. It appears to be a GL-4, low-sulfur oil, similar to what is used in some manual transmissions. This type of oil is used in manual transmissions because it is less acidic and does not attack some of the softer metals used for syncros, etc.

2. Nobody seems to know if any softer metals are used in the transfer case, or if it matters whether you use a low-sulfur oil.

3. Most people and even dealers just use the same GL-5 oil they use in the differentials, and there are no verifiable cases where this caused a failure.

4. Ravenol makes a GL-4 75W oil that seems to meet the OEM spec but is significantly cheaper and easier to acquire.

5. There are no verifiable cases where using the OEM spec oil from either Toyota or Ravenol has caused a transfer case failure.

6. If you buy a lot of Amsoil, you can get it cheaper, but it's still more expensive. There are no verifiable cases that show it is actually better or worse than other brands.

7. Royal Purple is another option that costs more. And it's purple. Some people like purple. I'm personally not fond of purple, but I don't hate it. And I don't understand why color choice matters for oil that should mostly never be seen. But hey, you do you.

These are the facts. Do with them what you will.

 

Synchromax costs around $20 (USD) a quart.

 

Do you count combined miles?

 

Not nobody. It does have one synchro. And a gerotor oil pump.

 

Thank you. Using regular hypoid gear oil isn't a good idea. I tuned out the Car Care Nut long before he got popular because he was full of shit sometimes.

 

So about the same as the Ravenol, but for use in manual transmissions that specify use of an automatic transmission fluid or other low-viscosity oil. Not sure if 75W would be considered low-viscosity. They don't even tell you what weight it is.

Well, there you go. Probably a good idea to stick to a GL-4 oil then.

 

Got this back from Motul when I asked about the compatibility of GEAR POWER FE 75W:

The attached documentation only went up to 2022 and the GEAR POWER FE 75W came out in 2024, but also meets GF-4 74W requirements. So 2 options from Motul I guess.

 

Anyone use this?
https://www.amazon.com/Bilstein-Feb...&sprefix=bilstein+gl4+gear+oil,aps,125&sr=8-6