It’s gonna be a good night. I smell the gear oil already. LF fluid going back in

I finally got my hands on a can of LF fluid here in Canada. I changed my T-Case oil to synthetic 75W90 (based on the recommendation of my dealer, as ‘that’s what our mechanics use here at the dealer’) and it was a big mistake. Why I was changing my T-Case fluid is part of another story that’s not relevant here, but I changed it to 75W90 as there was none of the Toyota specified ‘LF fluid’ available to me and I was told by my dealer to use 75W90.

I found out that on very cold mornings the transfer case struggled to shift, when it had not had any issue the previous winter in the same very cold conditions. The truck would simply not shift until such time as the lube warmed up a bit. This was a problem when trying to maneuver out of tight camp spot stuck in 4WD, or ascend a newly frozen hill, stuck in 2WD. The T-case has worked flawlessly at all other times.

I am now convinced the 75W LF (LF=low friction?) is not just in there for fuel economy. I believe it is there, perhaps also, for cold weather shift performance. Whether this is because it is straight 75W, or has special additives is not known to me. I’m guessing the latter based mostly on packaging and price.

Each time I was in my dealer I asked for a can of LF as I wanted to get the 75W90 out, and finally they had one in stock. I had had no luck finding an online source that would ship the oil to Canada. At the dealer, I was told they had to get it “from the Lexus shelf”.

Now LF Fluid naysayers consider these facts: the Borg Warner transfer case is made in the USA, as is the truck itself. Toyota is shipping this LF fluid all the way from japan, in a hermetically sealed tin can to put in a USA transfer case in a USA truck, and why? Why would they do that? Because it’s required for the system to work correctly, I would argue.

This post will be meaningless to anyone who lives in warm places like Hawaii or SoCal, but if you live in places that get very cold winters, I’m guessing you’d want to use this fluid.

I will report my findings after another winter.





Made in Japan!

 

People are also using Ravenol SAE 75W

https://www.ravenol.de/en/products/usage/d/Product/show/p/ravenol-mtf-3-sae-75w.html

RAVENOL J1C1003 MTF-3 SAE 75W Full Synthetic Gear Oil - 1 Liter for Manual Transmissions, Differentials & Transfer Cases

https://www.amazon.com/Ravenol-J1C1...W&qid=1564282447&s=gateway&sr=8-1-spons&psc=1

 

I know that’s an option, though Ravenol is also hard to get in Canada, so I would have to buy a case.

Honestly, I’m not convinced it’s the same stuff. I’m thinking the LF fluid may have other additives, but who knows? Toyota is going through a lot of effort to put it in there. It’s not like there isn’t a thousand great gear oil refiners in the states. Why bring cans from Japan?

 

I do think the Toyota brand has a better additive package. I used the Toyota brand in my transfer case as well.
I know of three people who are using the Ravenol and are not experiencing any problems.

 

https://www.bobistheoilguy.com/forums/ubbthreads.php/topics/4389571/Toyota_Transfer_Gear_Oil_75W_V

https://www.bobistheoilguy.com/foru...t-toyota-transfer-gear-oil-lf-75w#Post5118386

 

Good idea.

This is from another forum that I found



“I just wanted to chime in here because I have a failed transfer case and I know why. 2 years ago I had the "4X4 Service" done, which was both diffs and the transfer case. I had my dealership put in the generic 80-90 in all 3. 2 weeks ago I notice a howling noise and they said it was coming from the transfer case. It's a 2012 4Runner Limited so it's full time 4wd, has 77k miles on it and I bought it certified used so it is covered under warranty until 100k. They tore it down and found the bearings were worn down and 2 of the outer races were starting to spin in the case. I realize now after reading the fluid specifications it requires it cannot take GL-5 80-90, it needs the synthetic 75w Toyota calls for. Hopefully you guys read this and put the right stuff in or your going to be in trouble down the road after a flush.”

 

I’m using it. Ravenol lists OEM equivalent Toyota Part 08885-81081 which is the european 75W LF Toyota fluid same as the US

$96 08885-81080 Toyota Genuine Transfer Case Gear Oil LF 75W 1 Litre 08885-81080

08885-81080

Pic from Eastern EU

 

I've also had the ravenol in my t-case for almost a year. No issues with 4wd mode shifts even at sub 0F temps on a couple mornings, I plan to continue using it.

I'm sure the OEM oil is better, but seeing as the only trucks that get it are the tiny fraction that go out of their way for it, I don't think it's enough of a difference to matter. Hell whose to say they even use the 75W LF at the factory?

Maybe since Japan has resumed commercial whaling Toyota will be able to get their hands on the secret ingredient again and the price for it will go down.

 

I am sure your are right, however keep in mind the vast majority of these 3G Tacomas will still be too new to have had their T-case oil changes under normal intervals. So 99% of the trucks are running the factory fill.

 

I have done some research into gear oils, particularly on the "75W" requirement for the transfer case. I am about to acquire my third Tundra, a 2017 4WD. On my previous Tundras, a 2006 and a 2011, I used Amsoil

$28 75W-90 Synthetic Gear Lube - 1 Quart (Pack of 2)

75W-90 in all three gear compartments (front and rear diff, as well as transfer case). The 2011 actually spec'd a 75W-85 in the rear diff, but I checked with Amsoil - they still recommend their 75W-90. Redline makes a 75W-85, so naturally they recommend it for the rear diff.


When I saw the 75W requirement for the transfer case, I had some concerns about simply using 75W-90 as I have been before. This requirement became effective with the 2014 model year, the year Toyota did a "refresh" on the Tundra. Prior to that, the recommendation was for 75W-90.


I contacted BOTH Amsoil and Redline for their recommendation for a 75W transfer case oil. Both have NO recommendation for this compartment. Amsoil still recommends their 75W-90, stating it will offer a bit more protection than a 75W-85. I actually spoke to Redline's technical support line. They stated the reason they have no recommendation for the transfer case is that Toyota has not released the specifications for this 75W oil. He also stated that transfer cases have been known to have parts in them that require very specific frictional characteristics of its lubricant. Since they (Redline) doesn't know what those characteristics might be, they cannot formulate an oil, or determine if an existing product they have would be suitable. I suspect this is the case with Amsoil as well.


I also checked the viscosity ratings. Take a look at the following chart:

 

I have always understood that a 75W90 is supposed to behave like a 75W when cold, and a 90W when hot. I don’t necessarily believe this to be true, but it would be interesting to see the same chart comparing 75W to 75W90

 

I think the 75w LF is just a straight 75 weight oil, whereas the 75w90 multi viscosity is thicker at certain temps? maybe that's the issue with the shifting of the transfer case

 

Yes that is right, however when it’s cold the 75W90 is supposed to behave like a straight 75, and thicken with increasing temperature to the properties of a 90W. That’s how a multi-grade oil is supposed to work, though I’m no expert on the exact science. It was in very cold weather, before the truck warmed up at all, where I was having issues with the 75W90.

 

if you look at the chart the 75w max temp is -40C so if using a 75w90 multi vis. anything above temp of -40C the oil will thicken?

 

I shoved royal purple in mine. Maybe I should drain and add ravenol

 

if you aren't having transfer case shifting problems id leave it in, or use that RAVENOL 75w best price only need 1-2 quarts

 

Yes,

Thats what viscosity index modifiers do. They are polymers that thicken the oil with temperature. Some of the affect is achieved by blending different base stocks, but also through the science of these polymer additives.

The W in the oil spec stands for “winter”, not weight.

A 10W30 is 10 weight “winter”, and 30 weight when warm. This dates back to when people had to change their oil to match the season.

https://en.m.wikipedia.org/wiki/Oil_additive

 

that's probably the case then a straight 75w oil at 110 degrees F will still have the same viscosity, whereas a 75w90 multi vis will become thicker at higher temps or even at certain cold temps. that's why I always try to stick with the recommended Toyota service guidelines when I CAN this of one of those instances where u could have performance differences using other than rec'd stuff, most of the time slight variances in what the rec doesn't affect things

 

Yes,

For sure what I experienced just might be the difference between the oil weights 75W vs 75W90. I just didn’t want any more messing around with an oil other than the Toyota spec’d fluid. I did enough troubleshooting at the time to know it was only on cold mornings, and the problem went away once the oil got some heat into it, and never occurred again until the next very cold morning. If the morning was a warmer one, there was no issue at all.

I will have lots of time to test my theory this coming winter, and there’s every chance a switch to the Ravenol 75W would also solve the issue, if the issue is resolved.

 

Cold morning 3rd Gen Tacoma ritual. Start truck up, plug heat lamp into on board 110v and place heat lamp under transfer case. Lols.