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

Redline lubricants are a premium synthetic oil product for your automobile needs. I utilize it in my classic Alfa Romeo Manual Transmission. Redline surpasses anything that was available when my Alfa was new. It really clings to the gears and shifts effortlessly with no grinding. This product works for most manual gear boxes but always verify with your owners manual. Larry Hunt

I have a 2015 Scion XB (Toyota) manual transmission and changed it a few weeks ago and used that Ultra 1 GL-4 and my manual transmission started having clunky gear shifts. I just changed it to Red Line MT-90 that's actually recommended by Toyota and what a difference. Immediately felt the shifting smooth as silk. Oh well, live and learn. Buy what's recommended by the mfg because they know what they are talking about. My fault.

Best fluid. I use it in my 94 Miata and my 337 MK4 GTI. Noticeable improvement in gear changes and way less gearbox noise.

This is very nice transmission fluid and it made the shifts much smoother on my car. I would highly recommend this.

Replaced manual transmission oil in Miata 6-speed and it made a surprisingly big difference in shift feel. Especially noticeable when shifting to reverse.

Good product, price and fast shiping

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.

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.