Transfer case fluid concern

So I have a manual transmission the manual calls for the 75w transfer case fluid . The dealer on the last service 30k used

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

75w 90 on the transfer case . Which I’m pissed about so my question is it ok if they used that fluid on the transfer case or should I open a case with Toyota . I haven’t noticed anything crazy with the transfer case just at times noticed I was having issues getting it into 4h .

 

Wut?

 

Dude it's a Toyota not a Ferrari. Won't make any material difference. I intentionally used

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

75w-90 because it was cheaper than the OEM fluid.

 

I used 75w in mine. If it were my truck, I would have not accepted it

 

If you've got 5 minutes and a ratchet you can swap it for anything you'd like.
Toyota probably isn't going to have a whole lot of interest in your plight.

 

There are brass synchros in the transfer case that could be damaged by the wrong fluid. GL5 corrodes brass. But:

• Lots of people including most dealers seem to use 75W90 with no problems. My dealer had to special order 75 W LF, implying that they don't use it for service.
• High quality synthetic GL5 is less corrosive to brass than older fluids, and brass is more corrosion resistant than copper used in the Copper Strip Tarnish Test (ASTM D130-10)
• Older Toyotas called for GL5, probably with similar synchros (I haven't been able to verify that they do in fact have brass synchros). They didn't seem to have any problems. There are lots of problems with 4WD actuators on 4th gen 4Runners, but I don't think anyone is pointing to GL5 being related.

 

It is perfectly fine. I run GL4 in mine but GL5 is fine too. Yes, there is a synchro. The synchro is not working hard which is usually when sulfur becomes a problem. Using

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

75W-90 vs 75W is not a problem at all. It is a transfer case, they really don't care what is in them as long as they are lubricated.

Mine shifts into 4H better now with the thicker fluid than it ever did with the stock stuff...

 

^^^ Well there ya go……good to hear

 

so wondering so the 75w is more important I take it not the 90 so if I wanted to go to 130 basically I can ? In theory or u recommend just going to 90 ?

 

The 75W in the stock stuff is not equivalent to the 75W in the

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

75W-90. The 75W stuff is really more like an SAE 75 gear oil. I don't know why they put the W on there. The 75W in 75W-90 means that it's a SAE 90 weight gear oil that flows a bit better than a straight SAE 90 weight gear oil. 75W-140 means that it would be an SAE 140 weight gear oil that flows a bit better than a straight SAE 140 gear oil. Ultimately, the thickness when warm will be thicker on a 90 than it will be a 75, and a 140 thicker than both. I don't see a benefit to going up in viscosity even more, although there was a guy here who had 75W-140 in his by mistake and it ran fine. it's just a transfer case and ultimately doesn't have much load riding on the gears. The lube is pumped to keep all the things lubricated, but there are no high forces in there except maybe the planetary gear teeth in 4Lo.

 

So the W stands for winter not weight.

The additives in the lube have the lube acting like 75 SAE gear oil in the winter and 90 SAE gear oil in the hotter summer months

 

Correct on the winter part, however, none of those are similar viscosities when cold. 75W-140 will typically be about twice as thick as

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

75W-90 at 0 degrees C. Which is why the winter weight stuff often adds confusion. It's really just a rating, kind of like on a scale, but it's not proportional. All you can really gather is that when talking about the same weight oil with different winter ratings (75W-140 vs 85W-140 for example), the lower winter rated fluid will be thinner in cold temps. However, comparing different weight oils by their winter rating really doesn't equate to helpful information because it's not consistent and the two aren't related on different viscosity oils.

 

https://www.ravenolamerica.com/passenger-car-products/75w-gear-oil-ravenol-mtf-3/

https://www.grainger.com/product/46...62c9ca973b921192f6efacda10fae867&gclsrc=3p.ds

 

Many dealers use bulk 75w90 in the transfer case, including my local dealer. Doesn’t seem to cause an issue.

I used Redline MT-LV in mine. It’s listed as compatible with Toyotas liquid gold 75w.

 

Very true and viscosity scale is completely different than an oil scale

 

To OP who started the string, tell the dealership that you will be happy to bring your vehicle back to their shop to have the PROPER fluid put into your transfer case at their cost. First reason, 75W90 is way cheaper than 75W and they likely charged you some standard shop charge for giving you the lower cost item. Basically, they promised you a service with OEM parts and fluids and then switched to a different fluid without your consent. Second reason, they are not the same thing and will only feel the same to your vehicle in a narrow temperature range. The higher the viscosity number, the thicker the oil feels. Viscosity changes with temp and 75W90 has a wider operating temp range which sounds good but the 75W has two others letters after it "LF" which stands for low friction. Where I am in Canada we can have anywhere from -55C (-67F) to +40C (104F). In a wide temp span I have heard of guys having T-case activation issues running 75W90 where it doesn't like 75W90 gear oil. The 75W LF is better for your transfer case because it has a viscosity of 75 at low temps and maintains the same viscosity at higher temps. Think of it like the oil is rated as 75W75 and it makes way more sense. What does that all mean? The 75W90 will have a higher viscosity at higher temperatures as its properties change more with temperature than the 75W LF. A team of nerds decided the T-case works best with 75W LF so I will trust that team of nerds over some shop counter person or service manager trying to make a quick sale. Toyota needs to stock this stuff better in the Americas. If Toyota doesn't understand the need to stock it, alternatives are: Ravenol MTF-3 75W (hard to find in Canada, even Amazon only has it from time to time), and Redline MT-LV GL-4 75W. To others above saying it's fine, that is an opinion that might be based on driving in a climate that doesn't change much from summer to winter where the viscosity changes and LF formula aren't really critical for performance. For those narrower temp operating conditions, that's probably you haven't noticed anything weird with the slightly different gear oil.

 

it’s easy to find & buy


https://www.blauparts.com/ravenol-manual-transmission-fluid-mtf-3-75w-1l.html?gad_source=1&gclid=Cj0KCQjwsPCyBhD4ARIsAPaaRf3Q3_OFi1QgTG547sgxe6j1gBh3xxJC0EqaHTd-QpK5b4tbq3PgVF8aAgGvEALw_wcB

 

There is no reason to pay the crazy price for Toyota fluid, Ravenol makes fluid equivalents and is a fraction of the cost.

I ruined a “butter smooth” shifting 5 speed in my 88 SR5 by putting a GL5 fluid in it. Even after I went back to a synchromesh fluid it was never the same.
I was a Dodge/Jeep tech for a long time and some of the New Venture Gear manuals and the manuals in the Mitsubishi cars did not like GL5 in the transmissions.

 

When there was a big sale at the dealer last year I did pick up the Toyota transfer case fluid. They couldn't ship it but luckily I could drive in and pick it up. I typically do my own maintenance and did the MT (redline), front and rear diffs (redline) and the transfer case (OEM).