Transfer case fluid

I do most all of my own work, even spooning tires on my bikes and sometimes for friends, and am happy to help friends with projects. I just recently wrenched on a stranger's vehicle for the first time. That was a weird feeling. I just can't see how shops get into the IDGAF attitude with the potential consequences. But, everyone is wired differently.

 

Yup and also the more problem in the future the more money for the dealership (repair and sell new cars/trucks) so win/win for them.

 

I'm sure the engineers do pretty extensive tests using the manufactures gear oils under the recommended replacement intervals to insure no failures due to the oil. Imo, anything done way sooner unless very severe use is a waste of money and resources.

 

That's where a smart owner would check back on those work orders.

Still though, other than the OM requirement, we don't know the long term effects of GL5 in the T case. I am more than happy to stay on the spec fluid train, but who really knows outside of Toyota engineering if the special fluid is truly necessary?

 

agree!

 

I unscrewed the fillerplug on my tf case and perfect fluid dribbled out. Screwed it back in and left it alone. 36k miles. Maybe Ill do it at 50 but tbh that synthetic stuff should last a very long time w/o serious offroad use. If I do it'll be royal purple syncro or the redline fluid.

 

So is changing out brand new tires along with suspension. Interesting that out of hundreds of thousands of threads here there's not one debate on it. It's always a wise choice.

 

I did some research this weekend on this topic and thought I would share with everyone. Take the information here but make your own decision.

Most of the experts tend to agree on one thing: GL-5 oil is bad for a manual transmission with synchros in it as the sulphur additives will eat away on the softer metals of the synchros.

This guy is a trained Toyota mechanic and he gives a good explanation why you don't use GL-5 oil for your manual transmission because of synchros:

Which fluid to use for Toyota Diffs,Transfer Case and Manual transmissions - YouTube

However, where it gets confusing is that in the same video, he contradicts himself when he mentions that you can use the same gear oil that you use in the differentials in the transfer case as well - the Tacoma Transfer case has synchros in it (helps to shift from 2H to 4H on the fly)!

There is another (quite long) video of another guy taking apart a 2017 Tacoma Transfer case to reveal that there is some sort of synchro in the TC (link below - talks about it at around 31.09 mins).

Tacoma Transfer Case Overhaul - YouTube

GL-4 and GL-5 are NOT interchangeable. If you put GL-5 where you should have GL-4 it causes wear to the synchros. If you put GL-4 where you need GL-5 (such as a differential), you will burn out the gear as GL-4 is not slippery enough.

The "Toyota Genuine Transfer Oil LF 75W" that is recommended in the manual is specifically made for this Transfer Case, however, I could not find any information on whether it's a GL-4 or GL-5 grade oil.

Does anyone have more information on the Toyota brand oil, does it say whether it's a GL-4 or GL-5 on the label?

 

It does not specify...
My research leads me to conclude, it most closely resembles a next generation GL4 manual transmission fluid, as evidenced by the few fluids that claim compatibility(Redline MTLV, Ravenol MTF3, Royal Purple Synchromesh). VOAs indicate it is a non-synthetic Group 3 with a very robust and particular additive package, with nothing really coming close. Not to say the other options don't work; they might not need the additive package and make up for the lack of it in their base oil(Group 3+ synthetic).

 

Excellent research, but I recommend just using the Toyota transfer case fluid. That's what I did at 6k miles, and will do again at 30k. I did go with Redline products for the manual trans and front & rear open diffs.

https://www.tacomaworld.com/threads...6mt-fluid-change.481719/page-18#post-19527948

Cheers! Dave

 

I think that is not comparing apples to apples. One is a maintenance item and the other is to enhance offroad performance. You won't get much offroad benefit from prematurely changing out your gear oils, sure it's going to run smooth and everything but no added performance. Whereas doing suspension upgrades and tires will get you a lot more performance increase compared to the factory stuff.

 

I did the research so that I don't have to use the factory stuff. The dealer wants to charge $80 a liter for that stuff! Why?? What's in it that is so expensive? Also, as @splitbolt mentioned, its non-synthetic as per VOA testing so it shouldn't be that expensive in the first place. The Red Line stuff is $18 a quart and is full synthetic which means better performance and wear. The dealer themselves use

$29 75W-90 Synthetic Gear Lube - 1 Quart (Pack of 2)

75W-90 gear oil if they are doing the labor so they can keep their profits higher than using the factory stuff. So, no!

 

I use mobile

$29 75W-90 Synthetic Gear Lube - 1 Quart (Pack of 2)

75W-90 in my diff’s and synchromax in the transfer case. I’ll say that the synchromax was definitely well used after 28K and although my transfer case wasn’t noisy you could hear it go into gear for sure. Now with new fluid it’s quiet again and you can’t tell if it’s engaging or not, it’s smooth as butter again. I use 4 low a lot in the mountain range I hunt in, I might just start changing it at 20k to be a little safer. Diff oil was in excellent shape, could probably get away with a 60K interval, I don’t mud or submerge them.

Mobile 0W20 in the engine, and Klondike Synthetic ATF in the transmission.

My trucks been happy and trouble free since 2016 without any Toyota fluids. However it was also born on April 20th / 2016 so it’s got them “don’t worry be happy” vibes all around .

 

I think a lot of the cost is it being a seldom used OEM fluid imported from Japan.

 

It is odd. I just called my local dealer and he told me that they only have bulk 75W90 and use it in all three. They had none of the 75W TCase oil to sell me. He told me to put 75W90 in all three. I’m fine with the diffs, but may spring for an online retailer for the TCase oil since I only do it every 50k.

 

The 3rd Gens are getting a lot miles and nothing has been noted about the T cases yet. It might not matter? But, I do have the Toyota LF stuff on the shelf. I need to get my current bucket of oil recycled, then I will swap it in.

 

Update: I just did the TCase oil change with the Red Line Synthetic MT-LV last week. I shifted to 4Hi and 4Lo a few times and I did not notice any change in the engagement.

 

where did you get the Toyota LF at? Trying to find it.

 

https://www.oempartsource.com/ gave me the best deal a few months back. Hooked up with a couple friends to save on shipping, and we paid about $58 each, delivered.

 

From what i've been told the toyota LF transfer case oil in designed to work well in sub zero temps. If you never operate your truck in them, i would think most other brand oils of that weight would work just as well.