let the additive settle is your gearbox. you will feel the difference. and do some research on google, u ll find alot reviews on intl forums as LM is used worldwide. one common issues i found on forums was abt synchronizers slipping. And as this additive sticks to the metal surfaces, it cannot be flushed out wid simple gear oil change. you have to use some flush agents and 2,3 consecutive oil changes.
gear of my car gives whine sound, i wanted to used that but reluctant as i dont want to screw gearbox and synchs just for whine sound. As my cars gears are already very soft and dont want em to be slipping out. i can bear the sound but slipping gears can be a problem.
I can suggest you best GEAR specialist in lahore if u want, you can go there for resolving this issue. a very capable and honest man.