Hey there!

I am replacing my tranny and clutch and I have a doubt; I have seen many comments that state that manual transmissions need GL4 oil, the job has been done but I cannot find GL4 oil in here, just GL1 and GL5S, Autozone guy says that the manual transmission requires Dextron/Mercon III ATF. Do you know if that is true?

Thanks

 

Not true. I use and love Redline MT-90 or MTL for colder climates.

 

Thank you! Actually I do have a situation, I live in Mexico and the selection is terrible. Do you know if GL1 90 or Dextron/Mercon would work fine?

 

No i don't think so....how far are you from the border?

 

as far as i know 5th gens dont take ATF in the manual trans

GL-4 can be a bit harder to find but Amsoil, Royal Purple, and Redline still make GL-4 gear oils. i usually use Redline and the trans shifts better/less grinds after

 

Autozone doesn't carry GL4 in my area. Use Redline MT-90, get it online or if you have Baxter auto parts.

 

Amsoil in Mexico....? c'mon y'all? Royal Purple? Wtf is Baxter? we used to reuse spark plugs even if we had to enlarge the hole to make it fit....

 

i work with a guy from South America, the stories he has from Mexico are pretty good lol

synchros on his truck took a dump years ago when he just got into south Mexico. got a guy at a repair place to fill/drain the trans with diesel fuel and put new gear oil in it, bunch of metal/brass came out. he drove it back to Canada in that truck just fine. if theres anything i'll give guys from Mexico or South America, they can fix a vehicle with damn near nothing and make a good job of it to boot

 

I had the same issue and ended up finding some real good stuff at napa called sta lube. seems to be the only GL-4 I can find on the shelf. I was told to stay away from synthetic gear oils when it comes to transmissions. most of the part store gear oils are for differentials. ive been using this sta lube stuff from napa and it works real good. im at 204,000 miles and no grinds. where im at it goes for around $32 a gallon.


you don't need any super fancy gear oil in a manual tranny since synchros need friction to work...


in my crx I run a non synthetic ATV oil with no grinds at 290,000 miles and the car is boosted but has to be changed at 10,000 mile intervals according to the factory service manual...

 

Here's a thread on this topic from the 4th gen section. You will see my post about getting better results with a GL-4.

https://maxima.org/forums/4th-genera...gl-4-dino.html

 

You should ask yourself why the previous tranny was replaced. GL4 is the requirement, not GL4/GL5 combo, not GL1, etc. Sure you can put in other fluids and you won't immediately feel their ill effects. Take GL5, for example. It will work fine for several weeks, a couple of months, while it is slowly eating away your synchros. Then your tranny fails completely.

Stick to GL4 only.

 

I'm looking at the factory service manual and it says,


" API GL-4, Viscosity SAE75w-90 or 75w-85 " .



API Category GL-4 designates the type of service characteristic of spiral-bevel and hypoid gears in automotive axles operated under moderate speeds and loads. These oils may be used in selected manual transmission and transaxle applications.


API Category GL-5 designates the type of service characteristic of gears, particularly hypoids in automotive axles under high-speed and/or low-speed, high-torque conditions. Lubricants qualified under U.S. Military specification MIL-L-2105D (formerly MIL-L-2015C), MIL-PRF-2105E and SAE J2360 satisfy the requirements of the API GL-5 service designation.


also came across this paragraph




What should you do if you cannot find a GL-4 that does not include GL-5 on it's label?
My next choice,and one I almost did even though I have plenty of GL-4 80W-90, would be a SAE 50 oil that meets
CAT TO-4 specifications. My third choice would be a SAE 50 diesel motor oil of the highest API
classification I could find, preferably group II. As you will see on the graph below, the temperature
curve for a SAE 50 motor oil (or CAT transmission oil) and a SAE 80W-90 are very similar.

 

Either order your GL-4 from talkinghorse here on the org, shop around for redline, or use Napa brand GL-4 if you're in a pinch. It will work it's just a bit thicker, but it doesn't have the syncro eating GL-5 in it.

 

any GL-4 is fine plus he says he lives in mexico so he doesn't have to worry about cold weather affecting his shifting.


with the sta lube GL-4 my car shifts way smoother...