Red Line50304 MT-90 75W-90 GL-4 Manual Transmission and Transaxle Lubricant (MTL) - 1 Quart (2 Pack)

Great stuff. Smoothed my shifting out in my 2007 fj cruiser.

I looked at many soft-synchro, GL-4 options, and this worked fine for my 2009 Toyota 5 speed. Very slight decreased resistance going into rail slots, about same engagement speed, as with OEM oil at 90k miles. I am not an aggressive shifter, but I have not had a single accidental grind since upgrading. With OEM oil, I had occasionally had momentary synch resistance/grind over the previous 20k mi or so. I was concerned something might degrade, but not so. Smooth in sub zero weather too. No leaks for thousands of miles.Note Toyota manual claims more corrosive GL-5 is acceptable, but I didn’t want to chance it on a number of Toyota expert recommendations. Perhaps the few remaining newer manuals use hard metal synchros, but mine does not.Old oil had no bronze shavings, no discernible silveriness, just slight expected silvery sludge stuck to bottom of case as typical gear wear.

This is an excellent product for cars with manual transmissions requiring GL-4 rated gear oil, specifically for 75W-90 weight. Putting gear oil that is GL-5 or dual rated GL-4 / GL-5 can potentially cause damage to the soft metal components inside your transmission. The high sulfer content in those gear oils can eat away the synchros inside your transmission, making shifting more difficult. This gear oil is safe, and specifically designed for use in manual transmissions. It won't eat away any of the components, and it leaves your car shifting smooth.I mistakenly put a dual rated gear oil in my wife's manual transmission. I thougt I would be safe using a GL-4 / GL-5 rated oil. I left it in there for about a year before discovering my mistake. The transmission didn't shift very well, and it was making grinding noises while driving. I eventually drained the fluid and replaced with this. Upon draining the oil, there was a lot of gold colored flecks that came out with the oil. That was material from the transmission synchros. I replaced with MT-90. The shifting improved greatly, but the transmission had already been damaged too severly. I ended up having to replace the transmission. I drained the gear oil at the time of the transmission swap. There were no gold flecks with the MT-90. The damage had all taken place prior to using the redline MT-90 gear oil. The new transmission was filled with MT-90 as well, and it has not had any issues.Pros:-one of the few available GL-4 gear oils on the market-Designed specifically for manual transmissions-reasonably pricedCons:-None (for the oil itself)-not avaialbe for sale off the shelf at most retailers (not a con of the product itself at all, especially if you are looking to buy through amazon)Like I said above, if your car's manual transmission requires GL-4 rated 75W-90 gear oil, then this oil will meet your needs and be safe for your transmission.

Used in an NA and NB MiataNo shifting issues.

I bought a used 2007 Pontiac Vibe in 2021 with 140k miles, it always had a slight grind in the 5 speed transmission, when shifting into 3rd gear, the previous owner took good care of the car with all receipts of everything that had been done to the car, only problem was, when they changed the transmission oil they put GL-5 in it, I had read that others had the same problem, and after doing a lot of research on it, I thought what do II have to lose, after putting MT-90 75W-90 oil in it it stopped grinding almost instantly, smooth the shifts out in all gears and no more grinding in 3rd gear, I have to admit I was skeptical, that it would work, but it made a believer out of me !!! Redline makes a good product !!

2003 toyota tacoma Xtra Cab 4x4 - 2.7L - 5spdChanged all the gear fluids 2x-3x in my 180k mile taco over the past 2 weeks. I let the tcase & trans drain for a couple hours (hot) & it took about 1.3quarts in the tcase and a little over 2.6quarts in the transmission. You could get by with 4 quarts, but I like the feeling of pumping it in until it dribbles out (which took 4quarts point something total; so i'd order 5quarts). And here is what I noticed:1) An average of about 20miles worse mpg on an entire tank of gas compared to synthetic GL5 fluid (in manual transmission and transfer-case)(355miles @ 15.5 gallons vs. 375mi @ 15.5gal)2) Much smoother shifting in manual trans compared to other older gl4 formulas & newer gl5 stuff. The clutch contains a larger friction zone. Now whether this extra smoothness actually causes more wear or not I have no idea.I'm pretty sure, people worried about copper or brass in your syncros or tranny / t-case need not be worried with the gl5 fluids. Most gl5 fluids say safe for brass on the bottle. Having said that - there's an obvious difference between safe for 100k miles and safe for the 400k i'm trying to hit. EDIT: changed my mind. Worth 5 stars. Saw the Walmart fluid after 10k miles. $#%& the Walmart GL-5 especially in hypoid gears. I'm serious... don't be stupid like me. I probably took 10k to 50k off my rear diff life (which I expect 400k out of) by running walmart fluid for 10k miles @ 90 to 105mph. If you're not going above 75mph or towing you might be ok.A word about fluid change intervals just from what I've seen in my truck (toyota recommends 30k miles for all fluids):Rear Diff - 30k is likely a tad long for the rear diff (20-25k feels better) - but I regularly drive thousands of miles at 90mph. If you aren't towing, driving about 80mph, or doing other stressful differential (for hypoid diffs) driving then 30k is probably ok. @ 70k-150k miles the rear diff fluid was black as hell and saturated with fine particulatesFront diff - I barely use 4x4 (maybe 10x a year for 10 miles at a time. There was pretty much absolutely no wear on the front diff fluid in 70k miles.transfer-case - noticeable mechanical wear of oil (splashy - not thick like syrup), minimal particulates, but still good protection in 70k miles (change whenever)transmission - particulates and mechanical wear, decent wear on the fluid in 35k miles (stick with 30k-ish)Hope sharing that experience helps. Best of luck.P.S. - look at your power steering fluid (suck out the reservoir with a turkey baster & put in new stuff - drive & repeat). Ran 110k to 165k on the original ATF in the power steering system. That was risky.