Trans and Diffs oil???

I have a 95, 2.7, manual trans, 4x4 Tacoma. I am wanting to change fluid in the trans, t-case and diffs. I had decided on Redline MT-90 for trans, and

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

75w-90 GL5 for everything else. My question is, can I just run the MT-90 in everything? Looks like I would need 8 quarts if using the one oil, or 9 if using 2 different types??? Thanks

 

Redline MT-90 is

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

75w-90 Synthetic Gear Oil. You can use the same for all 4 reservoirs.

The Tranny and Transfer case call for 75w-90 Gear Oil GL-4 or GL-5.
The Diffs call for 80w-90 Gear Oil GL-4 or GL-5.

I used Valvoline 75w-90 Dino (regular old dinosaur) Gear Oil for all 4 reservoirs last night. $7 per quart. The 75w provides a little less protection than 80w, so I'll just change the rear diff every 10,000 miles, which will probably be overkill. I like doing maintenance. My stuff will never wear out. Fresh oil trumps fancy oil. Redline is over double the money.

 

I have a '96 2.7l 5spd 4x4 Taco that I'm preparing to change the driveline fluids in too. I did a good amount of research on the gear oil to use and arrived at Schaeffer #293 Supreme (synthetic) Gear Lube in 75w90 for everything. It is very highly regarded on the bobistheoilguy site, among others, and has passed various tests and analysis with flying colors. One test that impressed me most was that the iron counts were extremely low in the Schaeffer as opposed to the other various gear oils. To me that means my drivetline will operate more efficiently over time (less friction, less wear and higher mpg). I understand the point about changing the oil at more frequent intervals but I'd rather have the added benefit of less wear/friction even during those intervals.

I've seen it online for $12-$15 a quart, but I was able to source it locally for only like $8.95 from a local gear shop (I purchased 8 quarts if I remember right). The proprietor said he recommends it to their customers and can't speak highly enough of it. He said they sell it for just a little over their cost as a service to their customers. Said that he has seen Schaeffer oil smooth out gear boxes that historically have always had a reputation for harshness, where no other gear oil even affected them.

Amsoil and Redline are pretty well regarded too (not as highly as the Schaeffer in my research) but actually more expensive. I was originally planning to use Royal Purple until I started researching it. RP is loved by some but not so much by the techno-savvy oil guys. RP has actually failed some tests/analysis. I had heard of Schaeffer already due to the reputation of their grease, which I already run in my heavy equipment.

 

Do not use GL-5 spec oil in the manual transmission, it contains additives that will degrade the brass fittings in it. The Toyota specs specifically state GL-4 only.

 

I've heard this before. I have a 2000 manual transmission 4x4 v6 and in my manual it says GL4 or GL5. Do I run GL4 or GL5? Is there really any truth to GL5 degrading the brass?

 

GL-5 will degrade the brass synchros because of the additives

 

If it degrades the brass then did Toyota change something between 95 and 2000? Just wondering why my manual would state GL5 as being safe.

 

My manual calls our GL-4 only for the manual trans

 

I will have to double check mine.

 

It was that way in my '98 manual too

 

Any specific info about using synthetics in 1st gens. I have heard and read conflicting reports of the rubber in some of the seals (axle, wheel bearing, etc.) not being compatible with synthetics and therefore should be avoided in the older trucks.

 

See the picture of my manual. It says GL-4 or GL-5.
I'm sure I'll be fine with my cheap Valvoline 75w-90 Gear Oil that says OK for GL-4 or GL-5.

Obviously, use whatever you think is best.

I read some more here and some guys seem to think GL-4 vs. GL-5 matters more if it's synthetic. I'm using dinosaur oil.
http://www.yotatech.com/f116/gl-4-vs-gl-5-a-201741

Since it never gets under 40f or over 90f where I live, and I only drive 2,000 miles a year, I'm sure my transmission will be fine.
If I were racing and 4-wheeling for a living in remote Alaska, I'd use Mobil 1 GL-4 synthetic in the tranny and change it after every competition.

 

I think I am going to go with mobil1

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

75w-90 GL5 for the diffs, mainly because its $10.99 and can get local. I am going to order the Redline MT-90 GL4 for the trans and t-case. I have read that some think the GL5 is to slick for the trans and had much smoother shifting with the GL4 oil.

 

What GL-4 equivalent oil do you guys use? I find it hard to even find GL-4 anymore. The dealer recommends 75w90 / GL-5. Also, the previous owner always used a GL-5 equivalent and the trans shifts decent, it could be a little smoother.

Thanks

Edit: Did some more searching on here and found the redline mt90 GL-4 for the manual trans. Thanks again.