Red Line 50304 MT-90 75W-90 GL-4 Manual Transmission and Transaxle Lubricant (MTL)- 1 Quart

Get what you pay for, though pricey, irrefutable 'performance' gains: vehicle shifts much much much more smoothly now - no more 'crunchy' shifts, & all gears operate better in a wider range of temps as well. Prior to the fluid change, 1st & Reverse were the more difficult gears to get in to, especially in colder weather - before the fluid had a chance to warm up - now they all shift smooth as butter. I can also shift much faster as a result. Last little + is that the fluid doesn't smell horrid.

I put this in a 2002 Chevy Tracker (rebadged Suzuki Vitara) with a 5 speed stick transmission and lever operated transfer case. The factory specification calls for a 75w90 GL4 gear lube in both but a previous owner had put GL5 rear end gear lube in them. GL5 eats at the "yellow metal" brass/bronze used in the gear synchronizers in the transmission and transfer case. As a result of this the transfer case would not shift into low range and the 5 speed stick was very tricky to shift. Hard shifts, having to force it into gear, being stiffer when it was cold, just overall not smooth. I was worried because a friend with a Jeep had a similar occurrence and ended up replacing his whole transmission because it became unshiftable and wouldn't hold gears. Read a review of this Redline and it's specific use for manual transmissions. Figured it couldn't hurt and put it in the transmission and transfer case. IMMEDIATELY it was smoother to shift just sitting in the garage with the engine off. I backed out of the garage and was able to promptly push it into 4lo for the first time since I have owned it. Worked great and I backed right up a small hill without any trouble. Several weeks later it's shifting better and low range is back. I will say the transmission was obviously damaged and the transfer case is still not smooth going into low range but I CAN go into low range now and the transmission is definitely smoother. I can only imagine what this stuff would be like in a transmission in better shape than mine. It's not cheap but considering how hard it is to find GL4 rated 75w90 anymore (I bet your local parts store doesn't have it or has a few quarts at most) I'd highly recommend this Redline product.

Not much to say it is what it is cheaper than local auto parts store got here quickly

My 2007 Accord running ~12,000 mile-old Honda MTF was shifting stiffly when hot. Shifting was a deliberate, almost irritating process. Running MT90, shifting ease, smoothness, and synch speed is VASTLY improved; now it feels natural and effortless. I'm in S. Arizona so the 'thick' 75w90 is probably about right. Redline's lighter MT mixes may be better for cooler climates. Honda drivers should at least consider trying it!

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.

I use MT-90 in a 1954 and a 1955 MG TF. Highly recommended.

Works great

After a lot of online research, I bought this 75W90 GL4 (Red Line 50305 MT-90) gear oil back in 2020 for a 2008 Toyota Corolla with a manual transmission having worn out synchros. Just over 300,000 miles, it would grind every time it was shifted into 3rd gear, and frequently when shifted into 5th gear. When fully warmed up, one could usually avoid the 5th gear grinds and sometimes the 3rd gear grinds by shifting slowly, but this change in behavior related to temperature was rather small—as a rule, grinding shifts had become a regular and unavoidable part of this transmission's existence. It was quite easy to open the fill port and to drain the gearbox. The old fluid was brown and somewhat thick, although thankfully it didn't appear to have any chunks. This stuff was a clearish golden red and a bit thinner, and the transmission's shifting behavior improved immediately after installing this fluid. Now when cold, one could usually avoid 3rd gear grinds by shifting slowly, and 5th gear only ground if one shoved the handle quickly. Once warmed up, 5th gear wouldn't grind anymore, and 3rd gear would only grind if the driver shoved the handle quickly, although the shifter still felt a bit notchy. In cold weather, it would grind more/longer, and in hot summer weather, it barely needed to warm up at all to avoid grinding. Based on my research and this car's history, I believe that the shop that replaced the clutch back at 150k used the wrong gear oil—probably a heavy (like 85W140), generic (or GL5) gear oil that damaged the syncros over the years. For the longest time, I figured that was the best this worn transmission could do without being rebuilt. And then over the last few years, I gradually became aware that fluids have continued to improve since the specs and testing for older cars was done, and one could often upgrade to newer, thinner and more stable fluids for better performance, improved fuel economy, and extended life. I have since started running this engine on full synthetic 0W-16 oil (instead of 5W-30 conventional its specced for) and gained about 3mpg, noticeably less drag when coasting, and much easier cold winter starts in the process. Then I started wondering about the gear oil. Some people mentioned putting Synchromesh in theirs, but I wasn't comfortable going that far—it seemed overly thin and lost the important GL4 designation. I had my eye on the Redline MT-85 at the time I ordered this MT-90, but it seemed to be such a small change, I originally thought I needed thicker fluid to help with the grinding, and the reviews here on the MT-90 seemed more encouraging. Looking again recently (and after noticing how the grinding became quite temperature sensitive with the MT-90), I discovered Red Line made a seemingly perfect 70W75 GL4 (Red Line 50605 MT-LV) gear oil. Long story short, the transmission is now near 400,000 miles and hasn't ground a single time since I drained this stuff out and put that stuff in, even as we're approaching winter in Ohio and have driven it when below freezing several times already. Additionally, the shifter feels less notchy and more smooth, the car appears to have gained another 1mpg, while gear whine sounds the same as it always has. My recommendation (particularly in colder areas) would be to skip this product and just go straight for the MT-LV unless you know for sure you need the thicker oil. The Red Line MT-LV is significantly more stable, being only five points thinner than this MT-90 when hot, and matching the hot thickness of this MT-90 when cold. If your synchros are worn, you need a thinner fluid (to allow for faster displacement/grabbing), not a thicker fluid. I am sharing this here because I wish somebody had told me this several years ago and I could've saved $100 and some unneeded wear on this transmission!

Ottimo prodotto

私の車は2.6L入るので３本で使い切りれました。

Changed out the gl-5 transmission oil that was in my 2006 tacoma to this oil. With the old oil the truck shifted rough and slow, would grind into 3rd gear every shift, felt like a worn synchro. With this new oil the shifts are smooth and it just pops right into the gear. 3rd Gear goes in perfectly 95% of the time, sometimes get some feedback of the synchro when I put it in but its minor compared to before. Would Recommend it for any vehichle especially with brass synchros, but if your owners manual says gl-5 only stick to that. Great oil just pricey might be possible to find it locally for cheaper.

Viskas gerai.

Used it in my safari dicor. Awesome performance. but the price is on higher side.