I kno that i can use redline mt-90 in my trasnmission but could i also use it in my diff? If so, how many bottles would i have to get to fill up the tranny and diff? The reason i ask this is cuz I've never done it before and also because I have to order it so I want to make sure I'll have the right amount to work with.

thanks

matt

 

Yes, it works fine in a non LSD differential

 

Why only in a non LSD diff?

 

guess I could go ahead and ask this will putting redline 75W90 be okay in a 90GXL's diff?

 

From their website, it sounds like the best setup is MT-90 in the trans & 75W90 NS in the diff. I'd imagine both are within Mazda's recommended oil weights.

MT-90:
Popular in Nissan, Toyota and Mazda manual transmissions and transaxles as well as other selected applications, this is a 75W90 GL-4 Gear Oil that’s slightly heavier than MTL. Provides excellent protection of gears and synchronizers and its balanced slipperiness provides a perfect coefficient of friction, allowing easier shifting.

75W90 NS
This GL-5-type geal oil doesn't contain the friction modifiers for limited-slip hypoid (ie use in regular) differentials. This makes the transmission synchronizers come to equal speeds more quickly, allowing faster shifting and much easier low-temperature shifting. Can also be used in racing limited-slip differentials where weak spring design causes too much wheel spin.

 

on the mt-90 bottle it says not to

 

ya i read all that but also if u click something else and download the adobe file... the information completely contradicts itself. I could be wrong i read it really quickly... ok so what oil would i use for a LSD?

Also how much fluid does a trasmission need so i know how much to buy?

thanks

 

Since you have a Turbo II (according to your hidden profile ), that would be a Limited Slip Differential. Use this:



75W90

Our most popular gear oil, this is the preferred product in nearly all car and light truck differentials, both conventional and limited-slip. 75W90 is preferred for most racing applications. It contains friction modifier which is recommended for limited-slip units. 75W90 Gear Oil can be used in many transmissions and transaxles; however, other Red Line lubricants have better frictional properties for rapid synchronization. Exceeds API GL-5.

 

For your second question, the differential takes about 1 and 1/2 quarts, so buy 2. I just did my '88 vert, MT90 in trans and 75/90 gear oil in diff. The trans takes about 2.6 quarts.

 

not to take over someone else thread but from what I take putting 75W90 in my normal 90GXL diff wont harm anything right?

 

The other choice that I use in all my differentials (including my Lexus SC 400 and Toyota V6 Tacoma) is the Redline Superlight weight shock proof.

 

This is just kind of an idea I had maybe it would be good to have a thread in the archive going over the best fluids to use. Using the search I was mostly able to find what I needed. It took some time, but it might be a good idea?