I did a couple searches and couldn't find exactly what i was looking for. I have a couple questions.

What is on of the better synthetic transmission fluids I can put into my 1995 manual transmission 4runner?

How many qts do i need for the manual transmission?

Thanks!

 

Check out Amsoil.com

They have an application page that will tell you exactly how many quarts. You can use either their severe gear or, if you want a "true" manual transmission fluid, their mtg stuff. I think the difference is that a true manual transmission fluid has additives for better shifting and synchomesh life while a true gear lube has more high-pressure additives.

 

Amsoil is probably one of the best synthetics, but I'm not going to start a flame war over which is better; they are ALL better than standard dino oil. Redline & Royal Purple are highly rated as well.

 

I put some Redline MT-90 in my tranny the other day. I paid 10$ a qt by the way. 1qt in the t cast and 2.3 in the tranny.

Make sure its gl-4 tho, gl-5 is too slippery. (someone make sure i didnt get those mixed up, the gl part)

MAKE SURE TO GET THE FILL BOLT OFF BEFORE YOU GET THE DRAIN OFF!

 

Yeah you got it right Tubby. GL-4 is what you want, GL-5 doesn't work well with the synchro's.

I used Redline MT-90 in my 92 Pickup and it is good stuff, definitely improved shifting, but I think the PO had GL-5 in it.

Not sure if the MT-90 is the best way to go for the transfer case though. I think a GL-5 gear oil is better for Xfer cases, but stil MT-90 is better than most stuff you will find out there anyway, so your Xfer case should like it OK.

 

I've got Royal Purple in my 5 speed. As tubby said be sure you can get the fill bolt out before you drop the drain bolt.

 

I've read this thread and others where there is conflicting information, so I'm a little confused. I have two questions:

1) Why is GL-5 too slippery if it's listed in my Haynes and FSM as an acceptable MT fluid? Also, others here at YotaTech recommend GL-5.
2) I just bought Mobil 1 Synthetic GL-5/MT-1 75W-90 severe gear lube for my MT. Is that a bad choice, and why?

Thanks.

 

GL-5 is fine. The FSM calls for GL-4 or GL-5. There is some discussion that GL-4 helps your brass synchros stay alive longer.

 

Old thread but it gives me a chance to ask something.

Is it ok to add dino oil into a manual tranny that currently has synthetic in it?

 

I have heard a lot of conventional wisdom that says this isn't a good idea. However, when I researched it myself, I couldn't find a convincing or conclusive scientific argument against it. If both conform to strict industry standards, so I don't see why it would cause problems.

On the flipside of that, I also don't see much wisdom in making the switch to synthetic and then going back!

 

Well, I did some more research on teh internets, and came across the ASTM standard for MT-1. You have to buy the full article, but the abstract does say something important: http://www.astm.org/Standards/D5760.htm

I may have been blind but I didn't notice that before. So, though the M1 75W-90 gear oil would probably work in my truck, the transmission is original with 270k miles on it. The synchros are already a little rough, so I'm going to go for something that has specific properties to take care of them.

Does anyone know where I could pick up some Red Line MT-90 in the Seattle area?

 

I think synthetic and dino oils and gear lubes are compatible and can be mixed.

 

i think so too, the diff viscosity's dont mix tho,

 

I have a leak and am hopping it will slow down with dino oil back in there. I don't have the time or place to drop the tranny to replace the seal.