Transmission cooler, suspension and oil

‘21 tundra has around 11.5k miles. Had the truck 6 months. I’ve put just over 500 miles on dirt roads some in pretty poor shape towing a utility trailer weighing anywhere from 1500 to 5500 lbs. At 11k I installed the Bilstein 6112’s set at 1.3” lift in the front and the 5160’s in the rear. I had the dealership install the fronts followed by an alignment. HUGE difference in ride, cornering, and stopping. I bought them thru Excel Suspension. For a few extra bucks ($100+\-) they’ll assemble them at your choice of lift height. I could squeeze the factory rear shocks like an accordion after I took them off. They were toast. Going to install a transmission cooler hopefully this week. I’m using AMSOIL ATL 100% synthetic. Already did the engine oil/filter with AMSOIL including both diffs as well.
Anyone got a suggestion for the transfer case oil? The dealership wants $91.00!!!! a litre for their 75w and it only takes 1.6 quarts!

 

I Spoke to my local toyota dealership , they told me that they just use 75w90 in the transfer cases on the newer tundras , there has been lots of debate on the subject but ive had zero issues with running amsoil severe gear 75w90 in my transfer case

 

Don't use 75w-90 in the newer transfer case. Fluid is cheap compared to having to replace your transfer case due to using the wrong oil to save a couple bucks and I don't care what anyone says that's just the truth.

Just did mine with the toyota brand 75w oil. You can get it from sparksparts for 63.77 a liter

I used code FREESHIP and got free shipping but idk if that will work anymore or not, if it does, that's by far the cheapest place I can find it.

 

I disagree sir ,

Being an mechanic myself I deal with independent driveline repair shops and I have close friends who work at Toyota dealers . I've talked to them all about this subject and they all have the same answer , they all use 75w90 in these borg warner transfer cases .

There is no evidence of anyone needed to have it rebuilt after using 75w90 , You can't make it seem like using a very slightly thicker oil will destroy the transfer case .

In terms of fluid dynamics the difference between 75w90 and Toyota's 75w is so small .

These transfer cases are very old school and very basic internally . nothing special , no super tight tolerances requiring special 75w fluid

IMO the reason for Toyota suggesting the use of 75w was for fuel economy and ( less drag ) in colder climates

My thought is why spend ridiculous amounts of money on a fluid that's not realistically needed.

 

Or one can purchase the more economical Ravenol 75W transfer case fluid.

RAVENOL J1C1003 SAE 75W Gear Oil - MTF-3 Full Synthetic (1 Liter)

https://www.amazon.com/Ravenol-J1C1...t=&hvlocphy=9012570&hvtargid=pla-403119471251

 

He just got done saying he doesnt care what anyone says... me included.

I cant find a way around it. If he doesnt care what I say then...




... he wins the interwebs.

 

I make an exception, i care what you say because you always make me laugh with your comments, but I'll stand by my point. I'm sure toyota says to use 75w for a reason and they made it a point to change the fluid specs when they changed the transfer case, so I really don't see the point in saving a few bucks on a service you can do anywhere between 30k-60k miles. But what do i know some random person on the internet is more knowledgeable about the tundra than the people who designed it.

 

Appreciate the feedback. It’s true Toyota uses a 75w for better efficiency ie mpg.
I put the 75w90 in my diffs and my mpg dropped immediately. A 2-3% drop in mpg is to be expected according to AMSOIL. Mine dropped more than that.
So be it. I tow a lot and live in the desert sw.
I’ve heard of ravenol. They’re a German company that works hand in hand with Toyota in Europe. I’d like to compare the MSDS’s for the German ravenol brand and what Toyota markets over here. Another task for me! If I can get those I’ll post ‘em up.

 

I have Amsoil 75w90 in front and rear diffs, as well as transfer case in my 2020 Pro. I know Toyota recommends the 75w in the transfer case, but after talking with several mechanics (including Toyota techs who said they use 75w90 in all three), I decided to use the 75w90 in the transfer case. I haven't had any issues since I dumped and installed new. In fact, I believe it shifts to/from 4WD quicker then before.

 

Is there any difference in transfer case design from 2019 to 2021?

 

There is no difference in design

 

Roger that

 

Ask the dealer for a better price they sell me the 75w for $56.
I’d use the Ravenol 75w before I used a 75w90 oil.
I don’t think you’ll see any major damage over time with either but how smoothly it shifts is likely a concern.

 

75W-90 is 3 times the viscosity of 75W at 100°C.

 

This means nothing . by saying its "3 times the viscosity" is over dramatizing the point .

the difference in oil flow when comparing the 2 oils ( 75w to 75w90 ) is so minimal that its a mute point , pour the 2 oils in each hand blind folded and you will never feel the difference .
Incase you didn't know ... the "w" doesn't stand for weight , it stands for Winter . So in sub zero cold temperatures 75w90 will act like a 75 weight gear oil , when at operating temperature the same oil will act like a 90 weight offering better sheer protection between chains and gears .

Borg warner chose this 75w oil strictly for break in purposes and fuel economy , this has been mentioned in other threads by people who have contacted and spoke to engineers at borg warner .

Have you ever taken a borg warner transfer case apart ? let alone any transfer case ? do you know the inner workings of a transfer case ?

Its great that you can look up technical specs on oils , but it means nothing unless you know how gear oil actually works in a transfer case . its when Real world experience and true knowledge of the subject like some of us here have that can actually help the OP make a educated decision . Not just offering up a stubborn opinion like so many individuals do here on this forum about interpreting what the owners manual states.

 

Does Borg Warner state a recommended break-in period? I did the recommended Toyota 500 mile break-in. Does that satisfy the transfer case break-in?
I’ve got just over 11.5k miles of which approx 3500 miles was towing a 1500+lb trailer. I have approx 60-70 miles in 4H.
4L maybe a mile or two.
Do the transfer case and front diff gears and stuff turn AT ALL when not in 4WD?
On a side note: are you stilling running without a liquid to air transmission cooler or?

 

You can change it whenever the recommended interval says but honestly sooner the better , when I changed all my diffs and transfer case fluids they all had break in metal flake in the oils , best to get that out sooner than later .

The front axles spin all the time but there is an electronic actuator in the front diff that hooks it up when 4x4 is selected , and only half the transfer case works when in 2wd .

As for trans cooler , I installed the 2018 and prior thermostat assembly that bolts onto the side of the trans , I ran cooler hoses up to an aftermarket hayden cooler behind the grille , Part # 679 . so happy I did the cooler install .

 

I did the front and rear diffs but was doing more research for the transfer case. I appreciate your input.
I’m getting ready to do a cooler install similar to yours ie toyota thermostat and lines with after market cooler. I’ll probably take a day and do 5-6 drain and fills in the transmission with the AMSOIL ATL. No shop will touch my transmission for a complete flush or to put in anything other than WS fluid if they do.

 

That's exactly what I did , did 4 drain and fills with amsoil signature atf . Trans runs way cooler when towing . Plus I found shifting is better with the amsoil

 

I forgot to ask or maybe you mentioned already...did you use the AMSOIL severe gear 75w90 in your diffs and tc?

 

Yup I used severe gear in all 3 .

 

Never mind. Found it.

 

Ravenol is a reasonably priced overall solution:
https://www.blauparts.com/lexus-gx4...MInYXk0tPo8AIVFeTICh3L2gqcEAQYASABEgKjTPD_BwE

 

Reading the above provided ravenol link I learned this kind sir, there is no such thing as “Ravenol 75w transfer case fluid”. What??

The ravenol transfer case fluid DTF-1 is NOT compatible with tundras T/C. The bottle label only says ‘transfer fluid’ but the product link labels it as transfer case fluid (?)

However, the ravenol manual transmission fluid MTF-3 75w IS compatible with tundras T/C.

The DTF-1 transfer case fluid does not have a Toyota part# cross reference and the manual transmission fluid MTF-3 75w does.

I guess they just do things differently in Germany.
But then over here, we drive on parkways and park on driveways.

 

The Blauparts link above: https://www.blauparts.com/lexus-gx460-transfer-case-differential-fluid-change-kit.html, has the correct Ravenol products in the kit listed.

Both the Amazon link and the Blauparts link show “MTF-3” 75W and the appropriate Toyota part number. The Blauparts link shows “DTF-1” 75W-85 with the appropriate Toyota part number.