75w-110 in T-Case?

It's great to know.... That we have a resident engineer of fluid dynamics on hand, here on TW. Thanks for clarification.

 

I mean….you’re making uneducated guesses that someone’s transfer case won’t last as long on

$30 75W-90 Synthetic Gear Lube - 1 Quart (Pack of 2)

75W-90…does that not make you a fluid engineer of sorts as well?

 

I never said that. All I said was someone (Toyota) spec'd 75W as what should be used.

 

“I would say yes. Test have been done on components with what lubes flow best with tolerances. The reason they spec oil/lubes weights that are best for that specific part. They spec 75w is best, for that particulartransfer case. Just like 0-20 for engine.”

This insinuates that the t-case will work better and last longer on 75W than on anything else. That sounds like a fluid engineer.

 

That's exactly what I was trying to get across in saying. If someone else wants to run anything else. (75W90, 75W110, 75W140) That's their proragative. Me, (myself) I'm gonna run 75W only ( spec'd)as what you said your running as well. Let them deal with trying anything else.

 

not saying it won’t comply. Just don’t see why you want to change something that isn’t broken. 75-110 is almost 20% thicker/viscous when hot…how does this help in a t-case? A rear diff is a different situation.

 

75W is far more viscous when it’s cold than 110 is when it’s hot….How does it hurt?

mostly playing devil’s advocate.

 

I do t think it hurts. I meant that it’s really only 20% more viscous hot or cold. I run 75w-110 in the rear because I tow. Everything else is

$30 75w-90 Synthetic Gear Lube - 1 Quart (Pack of 2)

75w-90…been doing it through every thing I can throw at the truck for years. What I have discovered is that a more viscous oil will deaden sounds (like when I ran 85w-140 in the rear…zero gear whine after changing gears, 75w-90 has gear whine, 75w-110 doesn’t). It’s probably fine, but if it’s freezing out, like it was today (-3 F) the oil could be thicker than usual to get things moving. It feels like it this morning until things were warm…not sure it matters

 

When the transfer case used in the Tacoma was designed and originally released,

$30 75W-90 Synthetic Gear Lube - 1 Quart (Pack of 2)

75W-90 was specified.

Chasing improved drivetrain efficiency, Toyota changed specifications on many lubricants to lighter viscosities like 75W and 75W-85.

This likely included additional engineering of the fluids themselves to improve shear and protective capabilities in the thinner fluids and also included additives specifically for Torsen differentials (LT and LX are specified for applications that previously called for the same gear oil for example).

It is also likely why these newer fluids are much more expensive.

Use this information however you see fit.

Jeff