RED LINE Synthetic Manual Transmission 90 MT90 75W-90 GL4-50305 - 1 US Gallon (3.78 litres)

Product Information

https://cdn.opieoils.co.uk/images/variants/icon/redline/red-line-mt90-75w-90-gl4-synthetic-manual-gear-oil-1-us-gallon-378-litres-1.jpg An old post by Keoke on this forum recommended Valvoline VR1 60W in the summer and 50w in the winter. I put in 60w and that fixed the o/drive problem that you described on my car. If MT90 fixed it on yours then your accumulator seals are not quite as worn as mine apparently are.

RED LINE MT-90 is a synthetic manual transmission gear oil that provides outstanding protection for manual transmissions. Perfect for vehicles with notoriously difficult transmissions, such as certain Nissan, Toyota, and Mazda cars, RED LINE’s MT-90 gear oil solves the problem of hard gear shifting and allows for a smoother manual driving experience, even in cold conditions. This is the perfect 75W-90 gear oil for drivers seeking a solution to a difficult transmission that also protects and prolongs the lifespan of their gearbox synchronizers.Under this hypothesis, any given brand of oil would allow the tranny to work just the same as another, so long as the viscocity of both fluids are kept equal. MT-90 is not for use in differentials with hypoid gears but is good for gear and synchro protection, balanced slipperiness for easier shifting in cold climates and also excellent for high- and low-mile transmissions Compatible with petroleums and other synthetics. Appropriate coefficient of friction for most manual transmission synchronisers (other’s synthetic gear oils are often too slippery for proper synchro engagement) I found MTL around 20 years ago while trying to solve some crunchy gear engagement problems in a BMW. It solved the problem so well that I've been a Redline fan ever since. It ain't snake oil. It's an engineered product. Satisfies the gear oil viscosity requirements of 75W90, 80W90, 90 and motor oil viscosities of SAE 40, 10W40 and 15W40

Since most GL-5 gear oils for differentials are too slippery for manual transmissions, Red Line offers these products that ensure proper shifting while providing ultimate wear protection Satisfies the gear oil viscosity requirements of 75W90, 80W90, 90 and motor oil viscosities of SAE 40, 10W40, and 15W40https://cdn.opieoils.co.uk/images/variants/medium/redline/red-line-mt90-75w-90-gl4-synthetic-manual-gear-oil-1-us-quart-0946-litre-2.jpg Maybe I could do a 50/50 mix of MTL and MT90, which would give me a viscocity more or less in the middle ... the best of both worlds ... ? IIRC, Redline says flat out that the only difference between MTL and MT90 is the viscosity/intended temp range. Like Steve says, if the car is driven hard or lives in a hot climate, MT90 is prolly a better choice. But frankly, we've run MTL in BMW race cars where the trans tunnel actually gets too hot to touch in the summer, and never seen a problem.