Red LineRed Line 50305 MT-90 75W-90 GL-4 Manual Transmission and Transaxle Lubricant (MTL) - 1 Gallon

Amazing product! My 5 speed transmissions in two separate vehicles each developed hard shifting in second gear. Both I thought required rebuild. Changing the fluid to this GL4 fluid restored operation to like new performance. Gear oil does wear out and needs to be changed but manual transmissions with synchro require GL4 oil not GL5 rear end gear oil. Even most shops don't differentiate between them but it makes a huge difference in performance. Don't rebuild your transmission until you try this!

Why did you pick this product vs others?:Value

2003 Toyota Tacoma 2.7L - 4x4 - 5spd manualBox was well packaged and sealed in a plastic bag (think mine was double layer plastic).By far the best fluid to run in the manual transmission and transfer case. Seriously avoid supertech (walmarts fluid - especially in the differentials). The first time I put this in, I did a flush with walmarts cheap sythentic fluid (75w-90 supertech) for 200miles just to make sure all the metal was out. I would not recommend more than 500 to 2,000 miles on supertech. With supertech synthetic, I accidentally ended up putting 7000 miles on the rear differential which is a higher torque spindle-type differential in most trucks and the temps were incredibly bad. > 180F @ regular 90mph. Really you shouldn't take most spindle type differentials above 75-80mph because of the wear. With amsoil the rear diff dropped down to 120 for the first 15miles and then around 140 at 90mph. - this is with outside temps of 85+. No more steel flaking and rusting. I'd use amsoil in the transfer case and manual transmission but it's not as good as this stuff at the varying temps. + the transmission doesn't get hot like a rear diff with 210,000 miles. And the transfer case barely sees any speed or wear even at the highest mphs. Thank god for brass.Drain bolts are 24mm. I used a tekton 2ft breaker bar and a shallow 24mm socket. Also bought the u-joints for ratchets just in case.Best fluid (lowest temps & smooth) I've found for the differential is amsoil severe gear 75-110 (yes I know the manual calls for 75w-90). Also, 75w-140 has very weird properties. So bigger numbers are not always better.Used valvoline dextron VI for power steering, which is meh after 10k miles. Will change to amsoil.Mobile1 seems best in the engine from a cost and wear perspective. I usually get pennzoil full synthetic because mobile1 is sold out. Pennzoil is nearly as good for the first 3,500 then seems to degrade much faster.Every truck varies. My rear differentials were probably neglected from the previous owner and exceeding the payload rating numerous times or perhaps someone possibly did not try too hard to get the perfect backlash / etc from the factory. These are my recommended milage drain marks:15,000-25,000 rear diff30,000+ front diff (will likely look good for you)25,000 transmission40,000-60,000 transfer case (unless this takes you years as in acid is more of a factor than viscosity)30,000 for power steering7,000 for engineBrake fluid 2 years if you dare :pSave yourself $150-$400, help your car, and buy the good fluid and do the transmission, transfer case, and rear differential yourself. It's easier than an oil change. No filter required. Fill ports offer idiot proof over/under filling assuming you're on level ground. I do it in the walmart parking lot with a 7qt oil container. Some brake cleaner. Scotts shop towels. Gloves (yes plz). Some empty distilled water containers. And a funnel. Might need a partner to hold the empty containers up while you pour the used oil.The front differential requires 10mm and 12mm hex to ratchet attachments and is much more tricky to access. Worth it though. :)

I have used this in three different vehicles over the years.First was a heavily modified and tuned 2008 Cobalt SS turbo with the F35 trans. I tracked that car often, including high speed courses, autocross, and the drag strip. The fluid held up fantastically, and always shifted smooth and accurately. I also used the SSlowbalt for my commute at the time, which was 120 miles a day @80-85mph.I have since (sadly) sold my SSlowbalt, and mostly drive my wife's previous (now mine) car, a moderately modified and tuned 2012 Cruze Eco with the M32 trans, that we bought brand new. I have used MT90 in that since the first trans fluid change at ~50k (150k miles at the time of writing this, was changed with the same fluid at 100k, and about to do a third change next week.)This stuff shifts SO SMOOTH! I wasn't having issues in my Cruze before I swapped the fluid, but I did, and still notice, how much nicer the shifting feels compared to my buddy's 2012 Cruze ECO 6MT. This is 100% worth it. I have driven our Cruze to both US coasts, through 39 states, ontario, and numerous drives back home to Detroit from Lincoln, NE. I also use my Cruze for the occasional autocross event. Just all around smooth and quiet operation.I also have this same fluid in my 1999 Jeep Wrangler TJ with 213k at the time of writing this.The MT90 smoothed it out to the point where I was worried, because I was so used to that old AX15 shifting like a dump truck, or something haha. But not anymore! Totally smooth, no grinding on faster shifts (1-2 used to grind a bit if I didn't remember I was driving a brick and tried to shift it too fast). Now it doesn't matter if I accidentally shift a bit too quickly, because there's absolutely no grind at all anymore!My TJ isn't a pavement princess. I use it for what it was made to do, and I use it a lot. That trans gets a regular workout. It has been about 15k miles since I swapped it.TL;DR: If you like your manual transmission to shift like butter, quiet, and precise, buy this fluid.

Great product.