GL4 heavier than 75W-90???

[SmotalChaos]

Does anyone make a GL4 heavier than 75W-90? Preferably synthetic? I have an 05 tacoma with the 6 speed that gets notchy at temperature, even with Amsoil MTG. Don't get me wrong, it's not bad, but I'd like to see if I can get the shifts a little more fluid. Now, toyota actually recommends GL4 OR GL5 for the tranny. I was thinking of trying SVG in 75W-90 or even 110. Any other suggestions? I always liked Lubriplate products, but it looks like their synthetics are only available in straight weights. Maybe ill try one in the rear next change.

 

[aquariuscsm]

From my experience,thinner gear oils make manual trannies shift smoother. Don`t go atf thin,but you don`t want something so thick,that it can`t lubricate the tiny spaces in the gearing,etc,especially if your tranny has needle bearings. I tried a 140 weight GL4 way back when,and it would get hung in gear. Stick with the manufacturer`s spec when it comes to a manual tranny. If anything,I`d go thinner before I`d go thicker.

Amsoil MTG has worked the best for me,and it shifts the smoothest once it`s hot and thinned out. Take it from my experience,don`t go heavier. I tried Redline MTL one time(which is a thinner spec that what my tranny calls for) and it was almost as good as the Amsoil.

 

[bmwtechguy]

I used some 75-140 Amsoil SG in a worn Ford Ranger 5 speed that specified basically a 10W-40 motor oil. I was having a lot of whining in all the gears except 4th, and having synchro problems in third and fourth. I ran that gear oil year-round until I got around to the rebuild, which required replacement input and output shafts, synchros and bearing kit.

The heavier Severe Gear lessened some of the noises and shifting woes at the time, yet required getting used to shifting quickly to the next gear when the oil was cold, and then slowing shifts down as the oil warmed up. I guess it kept that box alive until the rebuild.

Has MTG in there now and shifts perfectly since the rebuild. BTW, the 5-speed unit in that truck was made by Mitsubishi. A lot of them had a Mazda unit, which spec'd ATF.

 

[wantin150]

Redline MT90 and MTL mix. 50/50 or use 2 qts of MT90 for every one of the MTL. I would start with the 2 to 1 mix and go from there. Redline gets better the second time around. You're trans will not like the Amsoil SVG mix.

 

[unDummy]

SAE50 truck manual gear oils can be found several points thicker then 75w90, can be mineral, blend, or synthetic, and usually are GL4.

I don't see the need for 'thicker' gear oil in the average NY climate. Don't confuse notchy with positive engagement.

Redline has the "NS" fluids in 75w90 and 75w140 so you can mix the 2 at any ratio.

Valvoline has a 75w90, pn vv820, which is worth a try. Its not a synth but is a 75w90.

Problem with this issue is that the tranny is shifting worse as it warms up(as the fluid thins out). Thicker fluid might help. Finding the real cause of your issue, whether shifter, clutch, drivetrain mount, or.... related, is a must.

 

[wantin150]

Sorry, missed the "at temp" part. The Redline mix in my 6 speed Matrix shifts great at temp but a little notchy when cold.