Hello everybody, I recently rebuilt my gearbox , new roller bearings , 4 point bearing , 1st gear dog teeth and synchro, only issue I have is that it makes a some kind of noise at 2000-3000 rpm . It starts on 3rd it is less apparent with 4th and in 5th its a minimal whine . The noise is a kind of the beginning of a whine , it does under title load and the same noise is heard when foot taken off the gas quickly . on 5th it doesn't make it on deceleration , only when accelerating at 2500-3000 rpm. The noise is really hard to notice but I am worried to keep it like that . Here are some pictures of the crown and pinion, could they be causing noise? Also I thought that the whine on 5th could be the crown and pinion , and the noise on 3rd and 4th be something other.

Hey man, sorry that I havent been able to get back to your questions recently... life stuff.

The machinest dye you used is not a good indicator, and your pattern is very unclear. I prefer Prussian Blue - https://www.amazon.com/Permatex-80038-Pruss...1218&sr=8-1

The grease actually displaces where the contact is made and does a far better job at showing pattern:
Click to view attachment

Do you have links to the videos you sent me? This is a good place as many people are savvy and can help answer.

Last time we talked, there was concern that your backlash was not correct. You asked if you could change that while transmission is in the car. You cannot. I would recommend starting with taking pics of you checking your backlash as it sits before adjustment and we can all help guide how to get it set correctly.