Manual transmission gear lube

Recent convert to Redline as well. I changed back in November and notice a improvement in shift feel. It's does take a bit to get warmed up though.

 

Thanks, but Toyota disagrees with you. Page 460 of my Owner's Manual clearly states my MT calls for "Gear oil API GL-4 or GL-5... SAE

$28 75W-90 Synthetic Gear Lube - 1 Quart (Pack of 2)

75W-90." With that in mind and based on years of first-hand experience with it, I'm comfortable with the fact that Amsoil Severe Gear is one of a number of lubricants that are well-suited for our trucks.

 

In my manual it says to use GL-4. 2015,5spd,2.7L. I went with the Redline GL-4,75W90,it has been smoother shifting in cold weather, both when starting cold and after it warms. I wish there was a more definitive answer,I hope that I am not doing damage to my brass syncros.

 

Problems can occur when GL-4 is recommended but GL-5 is used. Your use of GL-4, as recommended in your manual, makes this is a non-issue for you. You're good. Rest easy.

 

Maybe that explains why Toyota transmissions are the worst shifting MTs I've used. They probably shift as smoothly without synchros. You want to use GL-5 with brass, be my guest. I'll stick with GL-4 myself. Maybe Toyota uses something other than brass?

 

I haven't had any serious shifting-related issues or complaints in over ~200K miles spread across the three Toyota trucks I owned/own ('92 Pickup 5MT, '04 Tacoma 5MT, and '13 Tacoma 6MT). Admittedly, though, upgrading the latest/current one to a TRD Quickshifter definitely improved shifting.

I've never torn down my transmissions, so I'm not sure whether Toyota relies on brass syncros or not. I suspect not, however, in light of the Owner's Manual recommendation of "GL-4 or GL-5" and the absence of any problems in spite of (my) extended GL-5 use. Obviously, each of us will stick with what works for us.

 

Toyota does not make the transmission in the 05+ to ? generation tacomas, it is made by the Aisin company. The 2wd version that is in our trucks is also used in other vehicle such as the Camaro and the Cadillac CTS and they shift like crap too.

I replaced ours two months ago after years of grinding 3rd gear when shifting.

Reguardless of what Toyota says, they've made some questionable decisions before, I would never run a GL5 in the Aisin trans, only GL4 and change it every 30k miles.


For those interested it technically is a Aisin AY-6 , feel free to google "Aisin AY-6 Grinding" and have a read.

 

My 2012 MT is serviceable, and that's it. I've owned vehicles with 3 on the tree that shifted better, and that's saying a lot. Even a non synchronized 4 speed from the 50s in one of our farm trucks shifted better. I have no problems with the Toyota 5sp, but it's far from smooth. I guess as long as it has a long life I'll be happy enough.

 

I'm 66 years old, and don't drive like I did when I was 25-30. 64K miles, and NO ISSUES with the Aisin.

 

Ours had 194,000 miles on it when it was time to be changed.

I drive like a old man too as I drive a manual trans 1st gen Dodge Cummins which is about as smooth as a dump truck but I told the wife to let the RPMs settle between each shift then hold light pressure on the gear stick and it will fall into gear when it's ready. All in all the new one shifts same as the old, not bad just not like the old W56 in her '86 4Runner.

 

Note that says recommend in transmissions that require GL-5 not GL-4.
And the last statement is "Can be used in AXLES where GL-4 is recommended (not transmissions)..

So the previous statement that GL-5 should not be used in the manual transmission is correct since it specs GL-4

 

i always used redline mtl (gl4) in my 02 and it shifted much better with that fluid vs whatever was in there

 

No, it's not. I'm not sure how many times it needs to be said. Page 460 of the (2013 MY) Owner's Manual clearly recommends "Gear oil API GL-4 or GL-5... SAE

$28 75W-90 Synthetic Gear Lube - 1 Quart (Pack of 2)

75W-90" for MTs.

When in doubt about this kind of stuff, the best bet is to RTFM.

 

in the case of the 2013 you are correct but the posters 2015 does indeed recommend Gl-4 and since i have a 2015 I did RTFM

 

I made (essentially) the same point, on 17 Jan...

It is, however, interesting that Toyota changed the spec between 2013 and 2015.

I also made clear the reference on which I relied was my (2013) Owner's Manual, in the following exchange...

Given all of that and the fact that

$90 2005-2015 Toyota Tacoma With 4L Right Petrol intake air snorkel kit high performance system compatible kit Replacement black Rotational Molding (2005-2015)

2005-2015 owners weighed-into this discussion, your "So the previous statement that GL-5 should not be used in the manual transmission is correct since it specs GL-4" statement appeared overly broad. As it turns out, we're both correct, lending credence to the notion that RTFM is better than relying on Internet hearsay, at least when it comes to routine maintenance. (Obviously, mods are another matter.)

 

Agreed and it as you mentioned it all comes down to reading the manual.
Since both the gl-4 and gl-5 are both the same viscosity i am curious why they switched from the GL-5 in earlier years to the gl-4 in later..
Was there actually a design change that made use or brass as well as something to compensate for the greater friction modifiers in gl-5 vs gl-4??