Manual tranny oil change to Sta Lube 85W90

[aquariuscsm]

About 2 weeks ago I drained the MTL and replaced it with Sta Lube 85W90 GL4 gear oil because it was getting very notchy once tranny was hot. Magnetic drain plug had no particles on it at all (mirror clean!). Drained fluid had no particles in it at all,but when I poured it back into a large jug to store it,the bottom of the white bucket I used to catch the drained fluid had what looked like a few tiny pieces of rubber particles (kind`ve like the residue you see when you change out the washers on the hot water faucet knobs on your sink/shower).

Upon first startup of my car,input shaft bearing noise was gone. Gear shifts and transmission feel has smoothed out like day and night. My manual tranny really seems to love this thick GL4 oil. The shifter feels a tiny bit stiff on cold mornings for a minute or so,but once warmed up it`s incredibly smooth.

So...........so far so good! Much better feel than the Nissan MTF and Redline MTL.

 

[unDummy]

Thicker fluid will muffle a bearing noise.
The fluid might also climb a little better.
IMO, MTL is too thin for your application.
Nissan MTF should've been perfect, but your location and tranny, IMO, should've kept with a 90wt.

I've installed Coastal, Stalube, Pennzoil, along with marine GL4 gear oils with no complaints. But, GL4 availability is lacking. Its so much easier to find and simply use Amsoil MTG, Redline MT90, or a synth SAE50 truck gearbox oil.

Post back after 5k-10k miles with more opinion. I know a few owners who swear by mineral gear oil for manuals. I myself won't use anything but a full synth. So, your experience and comments are appreciated.

 

[aquariuscsm]

Hey unDummy,thanks for replying. I always look forward to your posts and answers to my posts. I`ve learned ALOT from you.

My observations/experience with thicker gear oil in my tranny is........so far the thicker the better. Tranny shifts unbelievably smooth when it`s very cold outside on first of the morning drives. So smooth that you can`t even feel the changing gears. BUT,it still gets notchy and input shaft bearing gets noisy once it`s good and hot and fluid is warm/thinned out,which leads to my next questions:

Who makes the thickest GL4 gear oil? Thickest I`ve ever seen is the 75/85W140 Royal Purple which is GL4/GL5. I`m VERY curious about trying that since I`m in south Texas and it will be getting over 100F here in no time at all. Plus,I have until October of this year to milk out the warranty on my tranny (which definitely has internal issues from the manufacturer).

What do you think unDummy??????????

 

[Kitto]

http://www.mobil.com/USA-English/Lubes/P...on_Fluid_50.asp

unDummy has suggested this b4.

But finding this is another story... I can yet to find it except to buy it in case...