SAE 80 = 80w90?

[82DMC12]

Group,

Another question, this time about manual transmission oil. I have a Renault transmission that specifies SAE 80 gear oil. Is this basically the same idea as 10W30 versus straight-30? the 10W30 having additives to help it flow at colder temperatures.

Is there anything wrong with using 80W90 gear oil in this transmission? 80W90 is something I see in stores, but if that is a bad idea then i don't mind ordering some from somewhere special.

Thanks for the help;
Andy

 

[Bror Jace]

80W-90 might be a tad thick. Not sure if you'd notice that, though. As you suspect, it's the second number that counts.

Red Line MTL is 70W-80. Might be a better choice.

--- Bror Jace

 

[82DMC12]

quote:

---

80W-90 might be a tad thick. Not sure if you'd notice that, though. As you suspect, it's the second number that counts.

Red Line MTL is 70W-80. Might be a better choice.

---

Bror,

Thanks for the reply. I take it SAE 80 is kind of an obsolete weight (the car is an '82!). I've heard good stuff about redline, I'll have to check it out.

Thanks!
Andy

 

[Grossomotto]

I'm a Red Line gear oil nut, as is Bror Jace, I'm sure. I've had great luck with a 50/50 mix of MTL and MT-90 in my Toyota trans. MT-90 is a bit thick and many have seen stiffer shifting in cold weather with straight MT-90. Like said before, MTL will most likely be your best option.


This is straight from the RL site:

MTL: "This 70W80 GL-4 Gear Oil (SAE 5W30/10W30 engine oil viscosity) is designed for use in manual transmissions and transaxles. Provides excellent protection of gears and synchronizers and its balanced slipperiness provides a perfect coefficient of friction, allowing easier shifting. Popular in many BMW transmissions and in most Honda and Acura transaxle applications."

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."

 

[Pablo]

I'll bet a good synthetic 75W-90 would work fine as well.

 

[par]

I've tried RL both straight and mixed in my 2001 Tacoma and was completely disappointed.

Went back to Amsoil and never looked back. The RL was 'notchy' compared to the butter smooth Amsoil.

 

[Ken2]

Andy,
It probably also calls for a GL-4 SAE 80 gear oil, right? The GL-4 oil is another obsolete spec with compounds in the oil that do not attack the brass synchronizers. Some GL-5 80W-90 gear oils have the old compounds that are corrosive to copper-based metals.

If you can't find the exact product your best bet is to contact an oil company and ask their recommendation. Or, find a European car repair shop that stocks the right stuff and will do the change for you.


Ken