Gear noise by inserting third speed

Hello friends,

first and first of all, I am very pleased to be in the forum and beforehand I tell you that my knowledge of mechanics are very few, so I ask you for a little patience.

Although my Seat Ibiza is from 2003, the engine has relatively little use (95,000 km), it has all the services made and in general the car feels and responds very well, however, recently I started having problems when they engage the third vel.! The 3rd Vel. Apparently it enters well, but that is when I release the clutch/clutch, which sometimes makes the typical gear noise by touching each other.

The mechanic tells me that the problem is apparently with a synchronizer?!? and that you have to lower the speed box to solve the problem which seems to be a expensive repair, however I read that possibly changing or re-leaking the oil of the vel box. Solve the problem.

I ask you for your help, because I don't want you to try to sell a "new speed box" in the Seat agency, which is very expensive! In addition, it could possibly be solved taking the Ibiza to a private workshop and disassembling the box, repairing only the defective piece.

Thank you so much!

Yes, it is very likely that the
pronwine is the synchronized of the third damaged speed, you have to disassemble the box to repair it, I do not think it is for the lubricant, greetings.