Switched to RedLine MT-90. Results

[hardtopte72]

So my 05 CE 5 Speed has around 103k of well maintained miles on it.
I did a manual trans drain and fill around 20k ago using Stalube GL4/GL5 75W90 because I had some lying around.

A few things I always noticed were a faint howl from the transmission whenever at cruising speed(I figured normal), rough shifting to 3rd gear, and rough engagements when the trans fluid was cold. Basically it felt kind of grindey and had the howl.

Here are my observations:
I drained out the 20k Sta lube and it looked like crap(the last drain and fill yielded nice looking fluid but same howl and engagement issues.
I refilled with 2 qts of RedLine MT90 (13.49 at Amazon) and went to go do some side work. I did all work from a cold transmission. On first drive I instantly notice the transmission shifts like butter. No roughness at all. Especially in 1st and 3rd gear where it was worst. And I got on the highway and my howl has disappeared. I figured I wasn't going fast enough so I cranked it up to 80mph and it is completely gone. The transmission feels brand new.

I will keep on checking to see if the other issues return but I am confident the issue is gone. For 30 bucks(including fluid transfer pump since I no longer have a lift) you can't go wrong.

I wonder if this can eliminate the output shaft bearing failures. Only time will tell.

[SuperchargedMR2]

I have used MT-90 in many cars & it's awesome stuff. You don't need the pump though, just use a funnel with a long piece of hose from the top of the engine, works like a charm & much easier then the pump which can be a PITA.

[invader]

Was your Sta-Lube 75W90 a synthetic? Even so, such heavy-duty differential gear lubes have a higher viscosity than specifically formulated manual transmission and transaxle gear lube.

Motul's Gear 300 75W90 GL-5 (ester based) has the highest viscosity index (222), and the lowest viscosity at 100°C (212°F). ENEOS, Amsoil's excellent MTG which I use, then Redline MT-90 are close behind.


-Synthetic Gear Lubes- Viscosity @ 100°C (cSt), Viscosity @ 40°C (cSt):

Amsoil MTG Manual Tranny Gear Lube 75W90 GL-4: 14.7, 84.5 (Pour Point -44°C)

Amsoil FGR Long Life 75W90 GL-4: 15.9, 122.6 (Pour Point -51°C)

Amsoil SVG Severe Gear 75W90 GL-5: 16.7, 109.1 (Pour Point -50°C)

Castrol SynGear 75W90 GL-5: 15.4, 117 (Pour Point -48°C)

ENEOS (Nippon) Premium Multi Gear 75W90 GL-5: 14.7, 79.9 (Pour Point -42°C)

Elf TransElf FE 75W90 GL-5: 15, 101 (Pour Point -51°C)

Maxima 75W90 GL-5: 13.89, 90.8 (Pour Point <-51°C)

Mobil 1 LS 75W90 GL-5: 15.2, 106 (Pour Point -39°C)

Motul Gear 300 75W90 GL-5: 15.2, 72.6 (Pour Point -60°C)

Motul MotylGear 75W90 GL-5: 16.7, 107.8 (Pour Point -45°C)

Pennzoil 75W90 GL-4: 15.3, 108 (Pour Point -42°C)

Pennzoil 75W90 GL-5: 15.7, 110 (Pour Point -51°C)

Redline MT-90 75W90 Manual Tranny Gear Lube GL-4: 15.6, 90 (Pour Point -45°C)

Redline NS 75W90 GL-5: 15.6, 95 (Pour Point -45°C)

Royal Purple Max-Gear 75W90 GL-5: 19.1, 132.3 (Pour Point -48°C)

[hardtopte72]

Stalube was not synthetic however I shouldnt need synthetic to have smooth shifting and no howling.

All in all this was great stuff. And seemed to be cheaper than the competition. Gonna run it for 10-15K and run another change on it.

[silver04rollas]

Have been using Redline MT-90 for the last 5 years and the transmission shifts as smooth as butter still. I could not be happier with it.