i have a t5 gearbox in my ef fairmont i only just got it second hand and it makes a loud wynin noise in first not so bad but second and third loud with a slight vibration i put the ATF 3 fluid in it with the nulon additive and seems to have done nothin i only have month warrentee on the box so need to know asap any ideas

noise is wear.

Different oils will only mask.

Best oil for the box is Redline Shockproof.
then Castrol Transmax Z
Penrite Extra Light gear oil
Dexron 3