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Red Line MT90 Manual Transmission Lubricant 1QT - Universal
Red Line MT90 Manual Transmission Lubricant 1QT - Universal

Red Line MT90 Manual Transmission Lubricant 1QT


Read 3 Reviews | 2 Q&As
Part # 50304

In stock!
Ships within 24 hours
Universal part

Features & Product Details

RallySport Direct is proud to bring you some of the best lubricants in the industry brought to you by Red Line. 

This is the very popular and highly utilized Red Line MT-90 Manual Transmission Gear Oil. This gear oil has been specially formulated to have the appropriate coefficient of friction for most manual transmission synchronizer that is combined with a great viscosity balance to help cure hard shifting issues in most manual transmissions. The MT-90 is a fully synthetic lubricant with a very high viscosity index which provides relatively constant viscosity as temperature changes to provide your shifts with a consistent feel through a variety of temperatures while offering optimal friction protection.



  • 75W90 - GL-4 gear oil (similar to SAE 5W40 / 10W40 engine oil viscosity)
  • Popular in Nissan, Mazda, Mitsubishi, VW/Audi, Lotus Elise/Exige, Toyota, Mendeola transmissions and Atlas transfer cases for off-road
  • Offers quicker shifts, perfect synchronizer coefficient of friction
  • Safe for brass synchros, as it lacks the reaction sulfurs found in most GL-5 oils that can cause damage
  • High-performance gear protection and longer synchro life
  • Helps eliminate notchy shifting even in cold conditions
  • Satisfies the gear oil viscosity requirements of 75W90, 80W90, 90, and motor oil viscosities of SAE 40, 10W40, and 15W40
  • Recommended for GL-1, GL-3, and GL-4 applications as well as where most special synchromesh fluids are specified
  • Sold individually in a 1-quart container




    Brand: Red Line
    Class: GL4
    Friction Modifier: No
    Type: Synthetic
    Volume: 1 qt
    Color: Yellow
    Mfgr. Warranty: No Warranty
    Condition: New Product
    Return Policy:



    3 Reviews
    4.7 out of 5 Stars
    5 Stars
    4 Stars
    3 Stars
    2 Stars
    1 Stars
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    1 of 1 people found the following review helpful
    Used this in My Evo X Shifts so much smoother! 8 years ago
    5out of 5stars
    I did my 60K fluid change on my Evo X GSR and did the Redline Trans Fluid Cocktail. Transmission feels a lot better and shifts very smooth! 2qt of MT90 and 1qt of MTL = Smooth shifting and happy driver :)
    Was this review helpful?
    Does what it's supposed to do 9 years ago
    4out of 5stars
    Jon M.
    I decided to try out this fluid for a change. It works alright, you really have to get it hot for it to shift smooth. It's winter here now, but I'm sure in the summer when the temps can get a little higher the gears will go in smoother.
    Was this review helpful?
    Love this stuff 9 years ago
    5out of 5stars
    I did the recommended 70k transmission fluid change and used the MT90 as the new juice. The Mazda3 transmission is already known to be incredibly smooth but over the last 20k I had noticed it was getting a tad notchy, especially when cold. Immediately after putting this fluid I could feel the difference. Everything is smooth as can be and I could not be happier.
    Was this review helpful?


    • Q: Transmission “lubricant”  Aaron Blumenberg3 years ago

      Can I use 4 quarts of this to fill the transmission in my 2004 Subaru STi? It says it’s a lubricant and not an oil, so I’m not sure. If not... recommend trans fluid for an 2004 STi?
    • Q: Transmission tank size  kingofkingz33885476 years ago

      I have a 2013 wrx hatch and I need to drain and fill the transmission. Any recommendations on which is the best and do I need to mix it with gear oil? And how many would I need?
      • 0 of 0 people found the following answer helpful

        A:  WRX transmissions have a capacity of about three and a half quarts. This fluid is not recommended, and we suggest using a 75W90 gear oil for the transmission.

        Zach G. @ RallySport Direct 6 years ago  
        Was this answer helpful?

    This Part Fits

    Universal Product
    This item is non application specific.
    Please verify compatibility before purchase. May require some modification for proper installation.