Peugeot 306 exchange box

Friends I need to know if my exchange box is evil or not. Or it is about to spoil
to put in 1st and in retro I sometimes have problems like that it sounds a bit and does not want to enter. I don't know if it's because the clutch is not very close, it seems that it is somewhat long. Most times it enters smoothly without problems but some others when I pass from 1 to retro for example does not want to enter I do not force it and put in neutral I move a little left to right and I try again and as it enters normal ... they will recently throw a little more than half of the box oil, the bottle was a galon room I think. I hope you can guide me

I do not think it is because of the level of Valvulina but looks like repairing the leak because they will surely be the pallier's seals, if it sounds a bit when starting back it can be of the clutch or the same synchronism of the march. Check the slack of rods or cables. If you say that the clutch pedal is high, it may be that the cause.