Help with transfer case oil

Hey everyone, I order some

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

Mobil 1 75w-90 for my front and rear diff to do myself. But I am wondering what I should use for the transfer case. I read a lot but just want an updated thread of choosing the correct oil, my manual stats 75w-90 gl4 or gl5. Should I just use the Toyota transfer oil that’s 75w? Or can I use the Mobil 1 that I’m using for front and rear diff? Also should I use gl4 or gl5? Sorry but need some help and some clarification on this beat up question. Sorry just wanna make sure. Thanks

 

It's the same oil that you use for your differentials.

 

While you probably won't hurt anything using a slightly different weight oil I would reccomend going with the manufacturer reccomended weight & grade of oil (75W-85 GL5 for the diffs and

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

75W-90 GL 4 Or 5 for the transfer case and manual transmission)

 

I use 75- 90 for everything good enough

 

Weird Toyota changed the fluid viscosity at some point?
My 07’ say

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

75w-90 is good for the Front.
Yet the 2014 calls for 75w-85?

Anyway, I didn’t run either one in the front diff.
But did use 75w-90 in the Transfer case. No idea what GL rating. Didn’t even look?

 

Look at Redline MT-LV for the transfer case. I would advise against using any GL5 spec oil, there is a brass synchro in the transfer case. GL5 oils can degrade yellow metals over time.

 

It’s an automatic, don’t think I could use the MT

 

I live in PA so I don’t know if the

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

75w-90 or 85 would be better or just stick the weight it calls for in manual,I was thinking that but after reading everyone uses 75w-90…..

 

Yes, in the transfer case. Not for the automatic transmission.
https://www.redlineoil.com/mt-lv-70w75w

 

I live in Michigan and used 75-90 in all

 

My 2015 manual actually states GL-5 only for the transfer case.

 

I can tell you that I haven’t had any issues running 80w-90 in the rear diff.
Well, other than a leaking axle seal. But I don’t not think that’s what cursed the leak.
I think the rear breather being stopped up caused that issue.

As for the front, wellllllll…….
Let’s just say I had issues. But I am running 85w-140
And that’s a different story. Had I to do it over, I’d went

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

75w-90

 

Redline MT-90 is a

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

75w-90 GL4 that would work also. Since you said in the op the manual lists GL4 or GL5. I'd still recommend GL4 for my reason listed above. I'm just giving you some options.

 

Another thing is the transfer case drain/fill plugs the same as the front diff?

 

I don’t know for sure. It’s been awhile since I did mine.
I have an extra set of washers for the transfer case sitting here. They definitely don’t look like the crush style you use in the front differential.

These are solid.

 

If memory serves rear diff and transfer case and 24mm, front diff is 10mm allen.
I just use the same gear oil in transfer case and both diffs, lsd additive in rear diff.

 

My 2011 states GL4 or GL5 for transfer case.

 

Where did you come up with this?

 

Our 2005 has been running

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

Mobil 1 75W-90 in all three boxes since their first oil change. No issues at all.

 

That info has been around for as long as I can remember. Just Google gl5 on brass. Not sure but maybe that's why the 3rd gen's now spec GL4. All 3 of the generations transfer cases are almost identical internally. I've had them all apart...

But hard to argue when there are trucks out there with 100's of thousands of miles.